I've got JBL reflect flow bluetooth headset. Whenever I connect my FR245M to headset, the watch resets volume to maximum.
Much better would be to a) not to touch volume and use what is currently set in watch or b) remember previous setting when paired to this headset or c) start with reasonably low volume.
Starting with maximum volume is pain in the ass because it is very uncomfortable. It starts playing right away... too loud. You have to remove your headset before from your ears before you attempt to connect watch to it otherwise you risk damaging your ears.
For some reason this combination (FR245M + JBL Reflect flow) disconnects about regularly 1-2 minutes into the run so you need to repeat whole procedure again (remove buds, go to volume settings on the watch to reduce volume then insert them back into ears).
Please Garmin do something about it..