The same issue here. I have a Macbook pro 16 (2019 model). I paid 5800$, and it's constantly crashing on two external monitors. It was fine in the previous version of Mac. I had some crashes occasionally with the older version of Mac as well, but not that frequent. The only trick for now is both monitors should be connected at the time of boot so if I want to disconnect it from monitors then I have to restart it. P.S: Both monitors are Dell. I don't think the brand of monitor matters but just FYI