GPS unhealthy signal vs. GPS glitch

I’m using Pixhawk4 with U-blox F9P.
I used to get a lot of GPS glitches so I disabled all unnecessary ports on the F9P side and it seems like it helped.
I also upgraded lately from arpucopter 4.0.5 to 4.1.3 and now I get Unhealthy GPS signal messages.
Are the GPS glitches (ver 4.0.5) and the Unhealthy GPS signal (ver 4.1.3) the same?
And what can be the reason for the Unhealthy GPS signal that I’m getting now?

Here is the, Nsat and Hdop from today’s flight when I got the Unhealthy GPS (I had 2 flights before, half an hour each, without any issue):