My experience mirrors many of the others here. I have an iPhone 11 Pro Max and all major (non beta) release versions of iOS 14 have resulted in issues with Bluetooth connectivity for me. This goes for car connections, wireless earphones, Bluetooth speakers, mileage trackers - you name it. I get intermittent disconnects from the equipment randomly.
My phone is less than a year old and I first called up Apple about this after iOS 14 came out. The basic troubleshooting steps were discussed and tried but to no avail. The only thing that has consistently, albeit temporarily, worked is either restarting or hard resetting the phone - I then get about a day or two max before the problem comes back.
Since my first call I have had about 5 more lengthy calls with them. During these I have been asked to do anything from run smart diagnostics through to complete factory resets and fresh iOS installs from a PC download via iTunes along with complete manual addition of all apps/services in this case. Nothing has fixed it.
Today was my latest call and wanted to share that after being forwarded through to a senior team member they finally admitted there is a known problem with Bluetooth in iOS - he specifically said they'd received loads of tech support calls about it. Up until this call I had been led to believe it was a glitch with my specific install hence my goodwill in running through VERY lengthy reinstall/troubleshooting processes to try to fix things. I am extremely annoyed with Apple - I have had every iPhone almost since the 3G and this has been the first to not work properly. I wouldn't mind so much if they had just admitted it up front but they've wasted so much of my time in the last 6 months, whilst still happily taking the monthly payments for a device that doesn't work properly. The indication today was that there was a team of really dedicated geniuses (his words not mine) doing everything they can to fix this. The solution I was offered was to just wait, possibly until iOS 15 (presumably September). They have said that the warranty only covers issues with hardware not software so that is the only option - not exactly great considering that Apple products are specifically designed to marry hardware and software seamlessly.
So in short, they know about this Bluetooth issue, it's taken them months to admit it to me and there's nothing that can be done about it until they fix it in a future software update - if they even can. A really disappointing experience considering that Apple pride themselves on service and offering premium products.
