When I try to share any document, the app brings up the login screen and doesn't proceed further even if I've provided the login details correctly. When I checked in the main app (i.e. opening paperless_share rather than trying to share a document from other app's share feature), it shows that I'm logged in successfully.
I'm attaching the relevant adb logs, please take a look. Let me know if you need any more information.
08-29 16:11:02.521 6607 6919 D PowerCheckerService: foreground, uid = 10579, app = com.quinncasey.paperless_share
08-29 16:11:03.028 4920 4957 I ProcessMonitor: onForegroundInfoChanged: ForegroundInfo{mForegroundPackageName='com.simplemobiletools.gallery.pro', mForegroundUid=10237, mForegroundPid=30481, mLastForegroundPackageName='com.quinncasey.paperless_share', mLastForegroundUid=10579, mLastForegroundPid=31337, mMultiWindowForegroundPackageName='null', mMultiWindowForegroundUid=-1, mFlags=0}
08-29 16:11:03.028 4920 4957 I GameBoosterService: onForegroundInfoChanged: Cur=com.simplemobiletools.gallery.pro last=com.quinncasey.paperless_share
08-29 16:11:03.028 6607 6657 D PerfEngineController: ForegroundInfo{mForegroundPackageName='com.simplemobiletools.gallery.pro', mForegroundUid=10237, mForegroundPid=30481, mLastForegroundPackageName='com.quinncasey.paperless_share', mLastForegroundUid=10579, mLastForegroundPid=31337, mMultiWindowForegroundPackageName='null', mMultiWindowForegroundUid=-1, mFlags=0}
08-29 16:11:03.045 4920 4957 D GameBoosterService: onGameStatusChange foreground:ForegroundInfo{mForegroundPackageName='com.simplemobiletools.gallery.pro', mForegroundUid=10237, mForegroundPid=30481, mLastForegroundPackageName='com.quinncasey.paperless_share', mLastForegroundUid=10579, mLastForegroundPid=31337, mMultiWindowForegroundPackageName='null', mMultiWindowForegroundUid=-1, mFlags=0}
08-29 16:11:04.880 563 563 D ResolverListAdapter: processSortedlist: ResolveInfo{81b901d com.quinncasey.paperless_share/.MainActivity m=0x608000}
08-29 16:11:04.881 563 563 I ResolverListAdapter: Add DisplayResolveInfo component: ComponentInfo{com.quinncasey.paperless_share/com.quinncasey.paperless_share.MainActivity}, intent component: ComponentInfo{com.quinncasey.paperless_share/com.quinncasey.paperless_share.MainActivity}
08-29 16:11:04.881 563 563 D ResolverListAdapter: addResolveInfo: ResolveInfo{81b901d com.quinncasey.paperless_share/.MainActivity m=0x608000}
08-29 16:11:04.881 563 563 D ResolverListAdapter: processSortedlist: ResolveInfo{2d423bf eu.bauerj.paperless_app/.MainActivity m=0x608000}
08-29 16:11:04.881 563 563 I ResolverListAdapter: Add DisplayResolveInfo component: ComponentInfo{eu.bauerj.paperless_app/eu.bauerj.paperless_app.MainActivity}, intent component: ComponentInfo{eu.bauerj.paperless_app/eu.bauerj.paperless_app.MainActivity}
08-29 16:11:04.881 563 563 D ResolverListAdapter: addResolveInfo: ResolveInfo{2d423bf eu.bauerj.paperless_app/.MainActivity m=0x608000}
08-29 16:11:06.012 563 563 D ChooserActivityForCts: ResolveInfo Package is com.quinncasey.paperless_share
08-29 16:11:06.013 1747 4815 I ActivityTaskManager: START u0 {act=android.intent.action.SEND typ=image/jpeg flg=0xb080001 cmp=com.quinncasey.paperless_share/.MainActivity clip={image/jpeg {...}} (has extras)} from uid 1000
08-29 16:11:06.025 1747 4426 I ActivityTaskManager: The Process com.quinncasey.paperless_share Already Exists in BG. So sending its PID: 31337
08-29 16:11:06.025 876 942 I ANDR-PERF-LM: MetaMeter: isValidAsync() 203: Invalid (hintID,hintType,appName,duration,appPID,appThreadTID) = (4225, 102,com.quinncasey.paperless_share,31337,1747,4426)
08-29 16:11:06.029 6607 6657 D PerfEngineController: ForegroundInfo{mForegroundPackageName='com.quinncasey.paperless_share', mForegroundUid=10579, mForegroundPid=31337, mLastForegroundPackageName='android', mLastForegroundUid=1000, mLastForegroundPid=563, mMultiWindowForegroundPackageName='null', mMultiWindowForegroundUid=-1, mFlags=0}
08-29 16:11:06.029 4920 4957 I ProcessMonitor: onForegroundInfoChanged: ForegroundInfo{mForegroundPackageName='com.quinncasey.paperless_share', mForegroundUid=10579, mForegroundPid=31337, mLastForegroundPackageName='android', mLastForegroundUid=1000, mLastForegroundPid=563, mMultiWindowForegroundPackageName='null', mMultiWindowForegroundUid=-1, mFlags=0}
08-29 16:11:06.029 4920 4957 I GameBoosterService: onForegroundInfoChanged: Cur=com.quinncasey.paperless_share last=android
08-29 16:11:06.029 4920 4957 D GameBoosterService: onGameStatusChange foreground:ForegroundInfo{mForegroundPackageName='com.quinncasey.paperless_share', mForegroundUid=10579, mForegroundPid=31337, mLastForegroundPackageName='android', mLastForegroundUid=1000, mLastForegroundPid=563, mMultiWindowForegroundPackageName='null', mMultiWindowForegroundUid=-1, mFlags=0}
08-29 16:11:06.057 1747 4434 W ActivityManager: Permission Denial: opening provider androidx.core.content.FileProvider from ProcessRecord{d7e68a0 31337:com.quinncasey.paperless_share/u0a579} (pid=31337, uid=10579) that is not exported from UID 10237
08-29 16:11:06.096 2863 2863 D RecentsImpl: mActivityStateObserver com.quinncasey.paperless_share.MainActivity
08-29 16:11:06.134 1747 1835 D ArtManagerInternalImpl: /data/misc/iorapd/com.quinncasey.paperless_share/1006/com.quinncasey.paperless_share.MainActivity/compiled_traces/compiled_trace.pb doesn't exist
08-29 16:11:06.144 1747 1835 I ActivityTaskManager: Displayed com.quinncasey.paperless_share/.MainActivity: +117ms
08-29 16:11:06.145 876 876 I ANDR-PERF-LM: FeedbackAPI: getFeedback() 60: app:com.quinncasey.paperless_share feature:AppClassifier feedback = 1
08-29 16:11:06.297 1747 1835 I ActivityTaskManager: Fully drawn com.quinncasey.paperless_share/.MainActivity: +284ms
08-29 16:11:06.872 1747 1828 I Timeline: Timeline: Activity_windows_visible id: ActivityRecord{7824dad u0 com.quinncasey.paperless_share/.MainActivity t55752} time:18581143