Water flow not updating in specific circumstances

Did not test other versions of the game, only 1.14.2. For some reason, water does not update properly in my creative superflat building world I experiment all my builds on. This happened after I accidentally blew my build up, and then I tried to rebuild it. Strangely, the water did not flow properly.

I can't seem to upload the video (too large) so here is a youtube link to the issue: youtube video

Sorry if the video is a bit bad, my laptop is pretty slow :/