Airpods cutting out - 1st Gen Airpods with iPhone 11 Pro iOS 14.4.2

Starting out with 100% charge on all devices and no battery or hardware issues reported through iOS, whilst on the move walking outdoors listening to audio only, one Airpod at a time, first the right Airpod will last around 4 mins then cut out with an abrupt crunch noise, swap to left Airpod and put right back in the charge case, the left Airpod will then last about 6 mins then also cut out in the same way, put left back in the case and get the right out again as it's ready to go again, this cycle will go on and on over and over, cutting out and swapping from ear to ear.

When using for phone calls outdoors these times are shorter, when indoors audio only is not an issue at all and they just keep going without a problem, but they will cut out in exactly the same way after about 20 mins on a call indoors.

The one thing I have noticed is when the outdoor temperature is lower (around -1 degrees C, 30 degrees F) the times are shorter and also when the wind gusts are higher the times are even shorter still.

Tested in various WiFi and Bluetooth free areas and they seem to have the same issues which rules out interference which many posts suggest could cause this kind of issue.

I know 1st Gen Airpods are old so maybe they just have had their day and it's time for an upgrade, let's see what 20th April / 7th June brings..... FPT! iUpdate! iBrows!

Anyone got similar issues or any ideas in the meantime?