Me as well. Brave 1.8.96 on Mac OS 10.15.4. Roughly 10 seconds every time; I think this has gotten longer over the past couple weeks, as though an ever-lengthening log file was being parsed, or some such,
I also see an issue Facebook where entry into a new post pauses for a few seconds and then moves the insertion point to the start of what had already been entered. Seems to happen in other browsers as well, so maybe unrelated,