I have a similar issue with live TV pause. Maybe it is helpful to know that mine started having problems when the TV automatically updated to version 14.1 from 14.0 about 2 days ago, perhaps this is relevant for you too.
Prior to this live pause worked fine, with animated thumbnails on-screen to help you find where to scroll to in the buffer, and with clear timestamps to show you where you are relative to the live position. Now both are gone. I have tried reformatting etc. but no solution. However in my case the core functionality of live pause is still working, it is just a lot less useable than before.
I happen to have a download of the 14.0 release for updating by USB, so hoped to be able to step back to that older release to regain this functionality, but the TV only seems to allow updating over the network. Even the secret menus offer no way around this blockage.
My TV is a Sharp 43" Roku TV.