Firmware 15.77 - Garmin says REST, on 3 days

Check your setting for long run days. A bug is adding more than 2 days/week. That will kill the algorithm. 

Long run days is enabled for SAT and SUN

i have never been there for any changes

how should i configure it as a workaround for this bug?

If there are only 2 days marked, you should not be affected by the bug mentioned by me. 

Try this: Daily Suggested Workout prompts not working?

Bear with it. I had rest for three days but this morning back to an anaerobic workout. 

Mine has rest every single day. I just said screw it and went back and to TSB charts until the firmware gets fixed.

How is your HRV? Has that been low? My watch has been constantly showing strained, detraining or unproductive as a result always says rest... I've had to ignore it where as previously I would have said the watch knew me better than I did. Now it's a stranger I just ignore.

Basically everyday since December (when 15.77 was installed) my HRV has been low, since all the recovery and training metrics are tied to HRV these features are now useless. I took two weeks off training in December and it made zero difference. 

Exactly the same for me. Something has seriously broken on their ecosystem. Please log a support ticket.... It sounds like there's lots of users there where this is happening but I'm not sure if Garmin get visibility... I've logged a ticket. They told me to factory reset my watch but it's been the same....

I use a custom training schedule, but often look at what the DSW is (it used to match pretty well, roughly aligning with the custom schedule), but now there are often repeated suggestions. Last week it was "base 75 minutes" on 3 consecutive days, and then a "long run"of 80 minutes. I won't report it because my not actually doing the DSWs may impact how this works.

I run by daily suggested workouts and it works without any bugs for me, my hrv is also balanced. Tactix 7 15.77 here.