I ran into a known issue it appears. I reported it a year ago and appear to be the only one with it :( https://github.com/RoboSats/robosats/issues/331
Discussion
lol and you were the one to report it too 😂 Seems to work fine on my TailsOS 5.20 machine using Tor Browser 13.0.4 (based on Mozilla Firefox 115.5.0esr).