The changes between 2.3.0 and 2.8.0/1 (at least as far as opening the scanner are concerned) were to cache the list of devices, in order to save a few seconds searching for them - on most systems they are identical every time.
On some systems, the device names change due to the USB IDs changing. You should see an option to turn off caching the device list. Please try that. If that doesn't get 2.8.1 working for you, please start gscan2pdf from the command line with gscan2pdf --log=log Reproduce the problem, quit, and post the log file, which assuming you have been able to quit properly, gscan2pdf will have compressed to log.xz
signature.asc
Description: OpenPGP digital signature
