HRV dropping - it is happening again

Yes. Dropped to all time low since i bought the device 2yr ago. Startet after update i belive. How to fix? 

There is no fix. It will last for several weeks and after that it will increase again. And meanwhile probably mess up your training

I have the same issue, but I follow my gut when doing my training. I run to feel or by my Stryd powerzones. If the Stryd powerworkout feels to heavy i slow down not to strain myself. 

Yes, of course you have to listen to your body. But if you have an adaptive training schedule (like a training program or just the daily suggestions), my experience is that it will lower your training load due to your "strained" status. And with that, your are undertraining yourself, and your stamina will decrease.

@Dako , according to my Garmin i was strained for more than a week and thus a very low training readiness. It was the week before my race and trained with my athletics club on the track and did someasy runs as well. The race went very well. So i don’t let it hold me back. Sometimes i think the values of the HRV end VO2 max are generated by a randomizer  e.g my VO2 max on the watch says 52 and the labtest with breathing gas analyzing gave me a score of 47. Race predicted by Garmin for the half marathon was 1:49 an my Stryd predicted 2:01 +/- 5 minutes. I finished 2:05. It good to see a trend in the values but don’t let them hold you back or the other way overtrain your self. If you run a long time then you body knows 

There are proven seasonal changes in HRV: [...] all indexes of HRV were found to be lower in the summer than they were during winter.  [...]

https://doi.org/10.1177/204748730000700209

FWIW, my HRV currently goes significantly up (but I am on the current beta version 21.16)

The most important is to learn to listen to the body, HRV is util but some studies shows that during the sleeptime the HRV are useless because of the sympatic and parasympatic nervous system, so what is more recomended is each morning after wake up, just sit relax and do the Health snapshot, it will show better the actual HRV, you can do it standing, some sais that is more precise in standing position, this is the actual HRV we need to know for how to training this day, you will see much different HRV from sleeptime and wakeuptime, i.e. the watch shows me that i had last night 63ms of HRV, wich is actual more low than my baseline, i just wake up, sit on the bed, make some deep breaths and started the health snapshot, the watch shows me an 81ms HRV, so from the speeptime it was low to aford a hard training, but with 81ms i have better idea how the body is, so i will no take much care about sleeptime HRV, im taking more the resting HR thats as an indicative of stress and fatigue if its goes up or viceversa.

Why do I have an expensive running watch, if I just have to listen to my body...

To have a GNSS tracker and a map on you handwrist. Because if one would seriously take into account all the measurement uncertainties and uncertainties of the used models you can just throw away all the metrics .

It's just a game of gaussian distribution and other statistics which will only represent your personal state by accident.