I am on Bedrock on Xbox one, and Windows on PC. v1.18.31 and a few minor patches after the main big update. This started a week ago maybe a few weeks at most.

It seems to be that the realm is not saving specific data about the world we use. Or that the realm is not letting the information upload when it brings up a save once we get on. Whenever the realm goes offline, (as in no one is on, so it saves the world and takes it off an active server) then uploads the save onto the realm, when a player gets back on. There will be things that did not save usually /gamerules and player data like the players /scoreboard scores.

[/gamerule commands I use on the realm]
Specific game rules will be reset every time without fail. This is just the main part of what seems to be the overall bug that is going on. I use...
/gamerule doinsomnia false
/gamerule sendcommandfeedback false
/gamerule commandblockoutput false
All normal 'in settings game rules' seem to save fine. (The ones you can change manually in the settings menu on worlds normally.)

[As for the /scoreboard scores.]
We have also had all the players score info just not come back once the world comes back online. We use many scores, and all players will have no scores on them at all. This specific bug does not happen every time.

[Commands]
Sometimes command functionality is just turned off all together, after we get back on. This only happens every once and awhile. But is destructive to my world given how many commands I use to keep things working.

[Other info on my realm's world that maybe relevant.]
-Default game mode is Survival. Some players in creative.
-Normal difficulty
-53 realm members currently (Most inactive) but have probably had hundreds come onto the realm over the years.
-Realm is up and active most hours. Maybe no one online once every other day.
-ChromaHills HD texture pack

[Video of me testing the /gamerule bug]
https://www.youtube.com/watch?v=IS1rxsel4aw