When it's raining, if you look through a glass pane or glass block the particle of rain falling turns invisible, although you can still see the effect of water hitting the ground.
I don't really play much on realms so I don't know if they are affected, but on my own worlds this has actually been happening for a while now.
We're tracking this issue as MCPE-56330, so this ticket is being resolved and linked as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
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