I couldn't get beorg to sync for some reason, so in an attempt to debug I uninstalled and reinstalled it (so, I know I have the most recent version). Now, opening it causes it to crash immediately. I've power cycled my phone, but no luck. I have plenty of storage available on the phone, so it's not that.
iOS 14.2, iPhone SE
There is a new TestFlight build which should catch an 'exception' thrown by the code which is crashing for you. I'm still not 100% sure why the exception is being thrown but this should hopefully stop beorg crashing with the only side effect will be some headings don't properly show links. If you do see any headings where links don't look right please send me an example so I can look at this further.