I'm using Photo Mechanic Version 6.0, build 3023 (40f5885) on a 3.2 GHz Intel Core i7 2018 Mac Mini with 32 GHz of memory, running Mac OS Mojave, 10.14.4.
The process of opening folders has a bug that has come with the latest build. Whereas previously PM worked like any other app, opening folders on the first try, now it doesn't. You have to go to recent items or back through the folder selection process to get the folder to open.
This is also an issue with ingesting images. Where the destination folder used to open automatically while the files are being ingested, now it doesn't. Again, you have to go to recent items to get the folder to open.
PM is a great tool. I'm looking forward to this being fixed!