I have copied this over to the 3.6rc4 thread
I have three vehicles running 3.6rcx /chibiOS, a 350 quad and a 550 quad with with PH cube and Edison/apsync, Here GPS. A large hex with PH cube and TX2/apsync/zubax uavcan GPS. All three work perfectly with 3.6/nuttx. Switching to chibiOS things go a bit off. The quads are set up almost identical, the small one now arms with log_backend set to 3 and ekf2 and ekf3 running. The 550 with rc3/4 sets bad logging unless I set log_backend to 1, with rc2 it works fine. The large hex is set up almost the same with the exception of uavcan gps, it works with rc2 and log_backend set to 1 but I get bad logging with rc 3/4 no matter what. If anyone would like to see a log let me know what bitmask to set that would be the most helpful. These are all long running craft that have proven solid fliers and have been through many beta versions. I have compared parameter files several times and can’t find anything that might cause the issue.