9.75 sensor drop out problem

There's lots of reports of this on this forum without any resolution from Garmin.  A change that helped me was turning off WiFi on the Edge itself (I never use WiFi to sync the 530 anyway).  Also for a while I also had to turn off WiFi on my phone before I started a ride, but lately that hasn't been necessary.  YMMV, so I'd turn WiFi off on both devices and see if that helps.  Maybe also try the "forced shut down" with a long press of the power button until it shuts down.  Good luck, it is very frustrating for those that have this issue.

Nice one. I will give that a try and report back! 

I had experienced multiple sensors drop outs (mainly powermeter, all 3 different models I own in different bikes) since I bought 530 in November 2021, through all firmware released. Finally my unit was replaced in May 2023 and issue disappeared. My suspicion is that it's hardware/chipset issue rather than software only, but Garmin will never say that

That sucks, sorry.  A factory reset may help, I've seen reports of that sometime solving mystery issues.  There is a thread somewhere about how to save your settings so you don't have to set it up from scratch again.  Also, as an aside, for the HRM I was having dropouts due to a bad strap, on average they only last a year for me before they start acting up.  I buy a "Powerlabs" replacement from Amazon, much better price.  I know you're having other dropouts, but perhaps the HRM also has a strap issue.  And finally if it still isn't fixed, call Garmin customer service, even if out of  warranty.  Every now and then they replace something that is beyond warranty, or they should at least offer a refurbished replacement for about half price (if you can stomach giving them more money).  Good luck, let us know how you do.

Thanks for your help.  Quick update.  

I noticed that I also started experiencing BLE drop outs on my smart turbo with my favero pedals linked to the Macbook.  Contacted favero and went through their triage, but it didn't make any difference - so perhaps the Garmin 530 isn't at fault at all?  Went back to the 530 Garmin and noticed that the pedals were connected via BLE, so I switched to ANT+.  Since then (riding in the garage on the turbo) the pedal power readings to the Garmin have been consistent - also to the Mac (to the Mac still via BLE).  Go figure.  The Garmin dual HRM has been solid too (that's always been ANT+).

I'm not sure if I'm cured - haven't completed an outdoor ride yet with this configuration.  I am more optimistic however!  I will report back again.

It happens to me, too. Virtually unusable with my Stages powermeter.

The switch to ANT+ appears to have fixed the drop out issue with the pedals.  Rode 235 miles on a trip last weekend without a glitch. Not sure why the HRM was misbehaving and that’s always been connected by ANT+. 

Glad your powermeter is solved.  Try a new strap if the HRM continues to misbehave.  The generic Powerlabs replacement straps on Amazon are only about $15 and it works fine with the Garmin sensor.