I'm having two issues with firmware 25.00 on my Fenix 6 Pro
1) Bluetooth HR connection dropouts during virtual run activity. I've had dropouts when connected via Bluetooth to an Apple TV and via my iPhone using the RunCline app. HR reads fine on the watch itself but shows as 0bpm on Zwift/Apple TV/iPhone for a random period of time and then reconnects.
2) During Strength activities, when pressing the bottom right-hand button to complete the first set, the watch reboots. This started when 24.10 was installed. It's not every time but is happening regularly.