It isn't just Fitbit
I only sync manually but my Alta HR became very reluctant to sync - and then screen cover came off (Oh and the strap started to irritate after two years).
So I cast around for a (hopefully cheaper) replacement and I bought an Honor 4 HR (as recommended by Which). It looks stunning, colour amoled screen and only £30. Well firstly the app requires one to
sell give away your soul by having to load Huawei's "play services" as well as the app. Fortunately I have an old phone with nothing else on it and, as said earlier, I only sync twice a day manually. Then one discovers that on the 19th August there was an app update that disabled permanent HR recording. Also it doesn't auto recognise anything. You have to tell it to start recording whatever sort of exercise you are doing and then it starts the HR, So of course the obvious thing is to start an exercise and never stop it (actually you have to do it daily). Then the real reason for disabling HR becomes apparent - the battery is flat after about three days. The watch is recording HR data during exercise and you can see your HR on the watch, but you can't then see it on the app. The daily HR graph stays resolutely blank.
I needed something under £100 that did at least what the Alta did - I bought another Fitbit, an Inspire HR. Which seems to be working just fine and, apart from the app displaying "searching for device" when it obviously means "syncing", it syncs much quicker than the Alta HR. It still sends the HR data to HQ to be <cough> processed, so it still needs two syncs in the morning (with a decent gap between them) to see whether one is still alive. Yes, the screen is nothing like as good as the Huawei but it tells the time and still auto recognises most of what I do in the way of exercise. And I can now wear it in the shower. Bonus.
For my limited use case as a historical exercise and sleep monitor it works just fine. And the battery lasts at least a week.