Lot of bugs on F945 since 3.90 ...

Quite a few comments regarding discharge issues. Search "battery drain" in the Forerunner 945 forum section.

Yes, I already saw those posts. But only about discharge issues.

In my case, I have LOT of others issues. So am I the only one ?

I feel the same like something is going wrong under the hood. I have had a couple of issues too, though different ones:

- freeze during activity (had to hard reboot)

- freeze of garmin express 

- some mp3 are not played anymore, which previously were ok (roughly 50%)

- very slow start up (was significantly improved when I reinstalled maps)

- radom switch back to garmin watchface

started around when 3.90 got installed. I think I will try to downgrade. Probably 3.30?!?

- Huge fast discharge of the battery (about 90% in a night !)

- The watch is very slow (it takes 5s or more to react each time I click on a button)

- The HR monitor doesn't work

- The compass doesn't work

- The automatic route doesn't work

Would you be able to elaborate on your above points? I understand you are experiencing these issues, but there isn't much for us to go on from your original post. 

We always try to recreate issues and if we cannot, we often ask for information from users in the form of logs and other information that aid us in escalating issues. This isn't only done through the forums as we also have Phone, Chat, and Email from our various support teams around the globe. 

Any additional info you can add would aid us greatly. Also, we recommend performing a hard reset (holding power button in until display is blank) before charging your device back up as an attempt to resolve your high battery drain. 

How can you downgrade the watch software ??

Here is the issue with the compass ... nothing moves on the screen, all is frozen

About the HR issue :

When I open the screen for HR diffusion, it's written either "--", either "33". But the number doesn't change. AND there is absolutaly NO light on the HR captor. It's like if the captor was disable (but it is up on the parameters).

And it's the same when I do an activity : there is the HR measurement !

About the automatic route ... when I ask the watch to define an automatic route, it's written that there is no road ... before, it worked

I think we can perform a manual downgrade, using the information of this link (see step #5 in the "Installation Instructions" section):

https://www8.garmin.com/support/download_details.jsp?id=14933

The instructions are for downgrading from a beta version. Maybe it's possible to downgrade from a release version using the same instructions (and files) from the link.