I don't think the rollback actually applied any changes since it failed partway through. Upgrading again finds no changes to make. Also, this nvidia driver issue was in journalctl from after the upgrade but before the rollback, so I believe it is the original problem, and not something left over from a bad rollback.
Edit: are you able to rename this post's title to "Nvidia kernel module not updating with package"? I can't seem to edit it myself.
Harvey nvidia version is correct, uname -r gives 5.6.19-158.current.
Yeah then either you're not up to date or its failing to install the new kernel image correctly. This usually happens when the UEFI partition is too small. But your not dual booting so that becomes less likely unless you did custom partitioning when you installed Solus.
sudo eopkg it --reinstall linux-current
See what errors if any it gives. If none try rebooting again.
No errors when running that, rebooted again to the same old kernel. uname -r gives the same output. EFI partition has 421M/500M free.
alex5nader
huh...
sudo clr-boot-manager set-timeout 5
sudo clr-boot-manager update
Reboot this time you'll have a menu. See if it gives you multiple options, if it does manually choose the newer kernel.
Harvey THAT WAS IT! Chose 159 from the two, and booted perfectly fine. Very glad to have this working again. Thanks so much! Is there anything I need to do to make it permanent, or will it automatically use the last one chosen?
alex5nader
Now you've booted into the newer kernel.
sudo clr-boot-manager set-timeout 0
sudo clr-boot-manager update
It should continue booting into this kernel now, after that. Super glad its fixed 
After that reboot again to make sure.
alex5nader If Timeshift was in the package manager then it may have fixed this issue. Actually Timeshift should be one of the installed apps when you install Solus.
RobertK a year old, but food for thought https://discuss.getsol.us/d/378-installing-timeshift-is-solus/29
