Currently on the Dec 4 build on Win10, which as of this writing is the newest it seems. Had a few instances recently where I'll go to use Steam and it just... doesn't work. If I had chat windows open or something those will stay working, but hitting any game icon that opens a steam protocol launch style, or attempting to open any steam window not already open, just quietly fail.

Also if I close say, chat that was open it won't open again. I have to go manually force close steam and the web helper processes and restart it to correct this. I could be wrong about this part, but I think it might have happened each time after the PC came back from standby, definitely did this last time but I think it did the other time or two this has happened now, but not 100% on that.