This is purely anecdotal.
When using MIT A12 Companion I find that Firefox , my go-to browser, drops the link between my computers (both my MAC and my Win10 laptop) and my phone as my data downloads. This is really annoying as I have had to start the downloads multiple times to get one to “take.”
When I finally tried using Chrome, this problem pretty much went away entirely!
Just sayin’
I noticed the experiences are very diverse from one user to another.
I use Firefox only because the blocks editor is way faster than when I use Chrome. But never had any issues with the connection on any of them.
Some people say Firefox is slower and Chrome is faster. At this point I think the computer configuration is the cause of so many differences.
It may also depend on which connection mode you’re using. The legacy option has the browser download the assets from the server and then send them to the companion. The new connection mode based on WebRTC sends the names of the files to the companion, which then downloads them directly (bypassing the browser). In the former case, browsers that are better at optimizing memory use will likely appear faster than those that don’t optimize memory well. Any browser extensions, as well as antivirus software that might be scanning any files loaded by the browser, may also interfere.