Every time I join my realm, I am able to do things from anywhere between 10 seconds to 1 minute before I am given this error. I contacted Mojang support and completed everything they had told me to do including restarting my computer, switching internet connections, uninstalling mods, uninstalling Minecraft altogether, making sure my internet connection was stable. I ended up having my friends also try to join the realm but they were met with the same error. I am able to play on other Minecraft servers with no problems and the realm was working fine until yesterday.

Update 4 December 2022: 

I have found that I do not get the error on a super flat world but only on other world types. I have tried saving the world, deleting the world from the realm, and then uploading the world, but then received the same error. I have tried creating new worlds that were not superflat including making a new regular world, and downloading maps from the map selector option. Each time I received the same error message that I have received every time. I have read in other online forums that realms sometimes mess up close to updates. Knowing that, I will update this page in 2 days when 1.19.3 is supposed to roll out and see if the problem is then fixed.

Update 8 December 2022: 

I am still getting the error upon entering the realm.