I’m currently on macOS Catalina, 10.15.7. I’m running the 1.7.7 installer of Obsidian, and I (by accident 
) allowed Obsidian itself to upgrade to 1.8.4. I’ve not experienced a lot of fatal errors yet, but I do believe I need to downgrade to 1.7.7 for both versions.
On the other hand, due to another experiment in my local setup, I’ve also installed Docker (ver 4.15.0 (93002)), and within that I’m running a container based upon obsidian - LinuxServer.io, and it should happily run any newer version.