I have had this issue for a while now and was hoping it would be fixed with one of the upgrades however its still happening. The first time I preview a topic it will show all updates, but if I make further updates to the topic and save when I preview the topic the updates aren't displayed. I have tried using the refresh button and re selecting the topic path but nothing works. I recently had issues with black screen timeouts and lots of crashes so I have recently cleared my registry, and appdata folders.
The only way around this is to restart Flare each time or create a dummy TOC to build and preview.
Has anyone else got this issue? I am on the latest 2021 build.