I'm still having this issue in 1.16.1, Windows 10 Edition
RE the Me Gold! achievement: This issue is likely a duplicate of MCPE-33382
Sorry, I found a duplicate issue: MCPE-54241
This sounds like a simulation distance issue. When you're several chunks away from these blocks, their behavior is disabled to reduce lag. Try increasing simulation distance when you're in your world by going to Settings -> World -> Game -> Simulation Distance
I wasn't able to get this achievement before (July 2020), but while trying to reproduce today I did get the achievement! I was on the same platform, Windows 10, so maybe the bug has been fixed.