HRV, low state for a long time

it changed your baseline and that is why you came into the green zone again (why does the baseline change anyway?). Still your HRV values are lower than before. I noticed my baseline got wider two days ago. from 44-56 to 41-61ms. My hrv overnight is around 38/39 (used to be around 50ms) So not in the baseline yet. And I am fit as *** :-)

What kind of reset did you do, and what data do I loose then?

I used the first reset option of the system menu ("reset to default values" if I translate correctly). It will keep the activity history, music, maps... But you'll have to configure again the wallet, all glances and directories, favorite activities, all data screens for sport profiles, the morning report, controls and shortcuts.... With few screen captures from GCM, it is quite straight forward and should not take more than an hour. 

The baseline started to decrease before the reset as it seems be a rolling average on 3 or 4 weeks.

What I found odd was the fact daily HRV values were decreasing more and more without apparent correlation with the training workload or rest level. After the reset, I can get better daily values even though the positive trend still needs  to be confirmed...

I reset because I was stuck again in an unstable situation with this 955.

I never had to do this with my previous 945: The problem with new algorithms is they are very sensitive to errors  but not sensitive or stable enough to detect real fitness improvements. 

Try this when resetting to keep setting activity screen setup.

forums.garmin.com/.../some-advice-before-upgrading-replacing-a-watch-or-a-hard-reset

I am not seeing cause for concern on my watch. I also doubt that a watch reset would change anything here (except maybe relieve some of the stress one might be experiencing about this apparent issue).

My HRV status has been responding to my alternating hard and easy days pretty consistently. I am posting my trends since end of September and the daily overnight average does zig-zag up and down as expected very nicely.

You can also see how the baseline has been moving down slighlty with the lower boundary moving from about 48 to 45.

Also your hrv drops from average above 50 to somewhere near 45. Look at my reports. First looks good, then a steady decline (without any reason), and last one clearly a dip because of Covid19. But over the whole period, a clear descent without a clear cause. the 11th of November I had a hard 21k race. SO that negative spike is obvious.

     For me, due to stress, maybe even seasonality, there was a drop in HRV values at the beginning of November, which has continued until now. 

   Over the next two months the baseline very slowly dropped and during this time the Training Status was unusable as it was stuck at "Strained" and towards the end it changed to "Unproductive" as my HRV was below baseline. I did not train intensely at all during this period, but I worked intensely.

     After two months the baseline drifted to the current HRV level and everything seems to be fine now. 

     To summarize, at the beginning the baseline was to have a green HRV of 50-62ms, now 45-58ms values are enough to get the same results.

But is lowering the baseline really the solution? That is kind of strange isn't it? Sounds like "if it won't fit, we make it fit". What is influencing the baseline. I know it is age, but what else? My HRV dropped from an average of somewhere around 55 to just below 40. That is huge, without any explanation! And for a few weeks now without any recovery.

Does anybody know what effect the training status means to the daily suggestions? I am "strained" for a while now due to the issue described in this thread. But I scheduled the daily suggestions to prepare for a marathon. I am a little bit afraid that Garmin now thinks I have to hold back the training load, and I will be under-training.

An update from my previous post. I have no answers. I agree that it would be good to understand why it's dropped - as long as the data is correct. Mine has been poor for a good while as shown, training intensity has been greatly reduced, as has duration. Nothing seems to improve it. I did some longish Z1 sessions and that seemed to bottom it out but then went down again. Had a few days rest and that hasn't helped, then an easy Z1 session sent it down yesterday.

Resting Hr hasn't changed. I did have a sinus infection and there was Covid in the house, 4 weeks ago, but I was negative.