I am a realms plus member and with the default texture pack my friends and I can join and leave without an issue. However once I back out of my realm to apply a texture pack everytime I join back up I get the same error code. Now if I rejoin on my ps4 I can join right back to normal. My friends however who are both on switch and ps4 will not be able to join and they get the same error code over and over again. The only way I've noticed to fix this is too takeoff the texture pack. Even then when I load up my realm I get an error code then when I re load it the error code goes away and I'm in my realm. And the same with my friends they'll get the error code once then after that first one they can join. So I noticed it's whenever I apply a texture pack.