I can’t find a consistent trigger for it as of yet, but sometimes when I finish with a dialogue box the top menu becomes greyed out and I can’t use it, so I have to click on Start (can probably be any of the other sections - I haven’t tested) and then back to Main to continue.
I have switched off Auto-run in this project (to limit the API calls!), but I’ve never had this issue before.
For example, in the below I added the filter action to Table 1 before it did this.