So basicly, I have a server on which I could previously earn achievements, but after updating both my client and the server to 1.21 I suddenly can't anymore, whereas my friends on the same server still can. (it could be it is to do with something else, but I noticed it after updating) Also the "Achievements cannot be earned in this world" tag doesn't show up.

I have tried the "Who needs rockets?" achievement and have gotten to 8 blocks and even higher a couple of times using a wind charge, but didn't get the achievement. I also tried progressing with the "Wax on, wax off" achievement, but the progress bar is stuck at 14/32 (I got there about a year ago) but isn't updating even though I have waxed and unwaxed all copper items (even the new 1.21 ones).

Edit: problem has been resolved after turning off private DNS in my phone settings, I read to try doing so after doing a bit more reseach.