Arrow keys on PC for navigation in Lightroom catalog and filmstrip dont' work

There are situations where you need to use Control with the arrows to navigate the filmstrip, usually with an active tool. 

Thanks for your reply. Resetting preferences wasn't successful either.

Using Windows 10 (version 10.0.19045)

Dell XPS 15 9560

Nvidia Gforce GTX 1050, studio version 526.98

Lightroom Classic 12.01

Sorry, I can't remember when the error first occurred or what was changed before it appeared. But I think it came with LR 12.

In a first step please try resetting the preferences of Lightroom Classic:   https://helpx.adobe.com/lightroom-classic/help/setting-preferences-lightroom.html

It's recommended to backup your preferences before you reset the preferences to the default settings: 

https://helpx.adobe.com/lightroom-classic/kb/preference-file-and-other-file-locations.html

What has been changed on your system before the error occur?

We need also more informations about your environment to say more.

Which operating system do you use?

Which version of Lightroom do you use?

Please post the exact version and not only phrases as "recent", "latest" and so on.