Garmin has purposely degraded GPS accuracy in firmware 18.16 ?

It looks like your GPS recording settings have changed - perhaps inadvertently as a result of the software update.

I would suggest the following settings to obtain an optimal track recording:

MENU > System > Satellites > All + Multi-Band

MENU > System > Data Recording > Frequency > Every Second

Also, make sure the settings for the App you are using (Bike, Run, etc.) are also set to these default settings.

With these settings I believe you will find the new software is at least as good as the old software, if not better.

HTH

@gaijin Thank you for your answer. But these are the settings I have had for the last seven days. The result before I selected recording every second and after, does not differ in the graphs.

I am really new to Garmin, but in these 7 days of use I've tested the GPS intensively in the mountains even in difficult cases, and even without using dual frequency, which my F7 does not have, I found the tracks accurate. Same settings suggested by gaijn, 18.16 as well.

Today for a run I set “System > Satellites > All Systems”, the track became many times more accurate, very similar to what it was before the update. I checked the “Satellites” value several times after the update and it was “All + Multi-Band”, tomorrow I will set it to “All + Multi-Band” again and come back with the results. If after the update the quality of data acquisition changed, but I had a different parameter, then now not a few people can train with this problem and not notice it. 

v18.16 + "All Systems"

And today I can see the “Power” data again, after updating to 18.16 it was only available in five workouts out of seventeen. 

In general my tracks are still as accurate as before the update. Yet I recognized some weird jumps/spikes when running through some longer and quite low tunnels/underpasses. Previously it was a straight line through the tunnel, because of losing the signal at the beginning and picking it up again when reaching the end. Now it’s more a zigzag line within the tunnel. It seems like it picks up a pretty bad signal somewhere within the tunnel, but actually it shouldn’t pick up anything at all. The runs were recorded with the SatIQ mode.
 

It was definitely a bug after the update, when “All + Multi-Band” is selected in the settings, but actually a different value works and the accuracy drops very badly. The problem is solved by switching to another accuracy mode and going back. Yesterday I selected “All + Multi-Band” again and got the recording accuracy as it was before the update. For myself I decided to keep the setting “System > Satellites > All Systems” and run with it, because in my conditions there is no difference in track accuracy.

@gaijin it stopped working again. Ran with the “System > Satellites > All Systems” settings today, the result is terrible accuracy, what is going on with the GPS, how do I stop this?

Hello. Did you uncheck snap to streets on the watch? 

My GPS is going weird things to. I noticed that they arrow on the map during a run was not on the trail I was in. After a few seconds it made a straight line from the Road the arrow was on to my exact location.

I did a few loops to see if it was of.... And and the map it was a straight line.