After updating to 4.6.0-beta1 I had the problem today (Tritilt VTOL, BZGNSS BZ-251 GPS / u-blox M10 chip, Mateksys H743 white), that could not be armed due to problems with the GPS configuration:
Messages:
GPS 1: probing for u-blox at 230400 baud
u-blox 1 HW: 000A0000 SW: ROM SPG 5.10 (7b202e)
Arm: GPS 1 still configuring this GPS
GPS 1: u-blox solution rate configuration 0x80008
GPS has perfect reception, status 4, 14-16 sats, HDOP < 0.85
Here is the short prearm log file: MagentaCLOUD
At home, I switched back to 4.5.7. stable, which did not have the problem.
To cross-check, I reinstalled 4.6.0-beta1, and the problem was back. To be able to fly with the VTOL and 4.6.0-beta1 for the time being, I disabled GPS_AUTO_CONFIG so that it can be armed.
On 2 other airplanes with different GPS (M8N) the problem did not occur when switching to the beta.
Rolf