Gamerules resseting to default

Recently, I have logging onto my realm world to find that all of my settings such as TNT or domobspawning have all been reset to their default values when I have logged on my world after leaving.

Steps (I did) to reproduce:

1. (don't know if this makes any difference) set randomtickspeed to 100
2. Logged off overnight
3. Logged back on
4. gamerules reset to default