This should probably be treated as a bug report. I've noticed that quite frequently Regex Autosuggest suggestions aren't shown, giving the precedence to other AS options. Before you ask - yes, I placed Regex Autosuggest at the very top of autosuggest providers in Settings, but it doesn't help.

Interestingly, if I click right mouse button and select "Show Regex Match Suggestions", all the possible suggestions are there, but many of them don't appear while writing. The situation can sometimes be rectified by going back to the previous segment and trying again. It seems like Regex Autosuggest is in a way blocked by other suggestions.

The same is true for QuickPlace function. If I want to use it while writing and the Autosuggest list is open, then CTRL+ comma doesn't work. I first must press Escape to turn off the suggestions window and only then QuickPlace can be used.