On Beta 2.72 and the watch just ignores my HRM-Tri. Before the beta I had the strap connected to the watch, after though, it looks as it removed the strap from my list and won't even recognize it when I tried re-pairing it. My strap is a bit old so I figured maybe it finally died, but I went and tried to pair with with a number of other devices (F3hr, my phone via Strava and map my ride) and sure enough each one of those are catching the signal. Tried restarting the watch and see if it that might have fixed it and it didn't. Anyone else having the problem? I'm just asking so I don't needlessly email the beta team with the issue. At least I can tell them then it is either just me alone or others are having the issue.
I believe you should mail this to Beta team anyway. I have HRM-Tri and no problems, but if you have issues and if it is related to the beta then someone else might suffer from that issue after the SW is final. So better to let them know as soon as possible. I hope you get it solved quickly.
Had the same thing happen to my power sensors after the update the sensors were removed from the watch I can add them bact they just wont connect. I also dropped the BETA team an email.