v-usb in CDC and timer issue. about v-usb HOT 1 OPEN

I know this is like a year old but I came across this library for my own projects to little success. All this failure is supported by the last paragraph of the project from nearly a decade ago you've linked, you'll realize the problem where it says:

The back door to the low-speed bulk transfer is gradually closing on the newer OS. After enjoying this USB technology, switch to the HID protocol or to MCU having on-chip USB controller.

V-USB is getting harder and harder to implement due to the fact it is tied to low-speed protocols. There's a reason OBDev doesn't really have this project on their front-page anymore. Even their marketing points are outdated and might as well be false advertising to some degree.

If you want to implement USB functionalities I'd recommend you try a dedicated chip (they are incredibly small and aren't even $1, even bundled with a board like Digispark's) with LUFA to program the firmware interface instead of using this fidgety thing.

In the case you're working with something like Arduino UNO for the USB serial programmer interface on the 328p, such a chip is already there and ready to go into Device Firmware Upgrade mode, making V-USB redundant.

from v-usb.