GPS Position Runaway

Hello together,

in the last days i did some testing with my Reach Units. After some time with quite good results the position began to runaway.

With runaway i mean the stabel position i had began to move quit fast away from my position.

I did a test overnight starting at ca. 17:30. At around 19:30 (while i had a stable fix for about 1.5 hours) the position began to move more then 20 meters.

Have somebody an Explanation for this behavior?
Or do somebode else have the same Problem?

At the Moment I use the ReachView Version 2.2.5

At the moment I have some trouble converting the ubx and the RTCM3 file to .obs files. So I will add this files to the Post.

Thanks for answers

Did fix drift that far?
If not, its probably satellites getting out of view, beeing blocked and/or combination of bad geometry and AR has bad correction data in the loop.
Fix&hold may also push fixed position out of place.

My fixes seem to drift also, If not fix and hold what should I use. My goal is to set up a base over a ground control point and and then connect with 915MHz radio to my Drone/Rover setup.

No my fix do not drift.

The quality drops to float or goes for a short time to fix and then again to float.

As far as I can see the satelites are still the same on the Rover.

Here is the Link to my loggs: