'Please login in Xbox before joining server'

I downloaded Minecraft from play store and i login and i join server and Minecraft said " sorry we couldn't validate your login " how to fix

I actually discovered a way to login.

Before opening the Minecraft app, switch for mobile data and login into your account.

After the login, turn the wi-fi back on, and you'll be able to play normally in servers.

Hi and thanks for reaching Microsoft Xbox gamer's community. My name is Josef.
I'm an Independent Advisor and a Microsoft Xbox user like you.

Hope you're doing great today despite this EMMA835

Please answer the following questions to assist you properly :
Where are you located physically? (Country)
Is this happening with an specific server? Or with every minecraft server?
Did you tried sign out and sign in with your account on Minecraft PE to see if that does the trick?
Or what about using a different wifi network?
Or what else did you tried so far to fix this?
In that way I can advise you different things or how to proceed

I’m in the United States

I can not join any servers at all

Yes, I’ve signed out and back in several times

I’m not able to use a different WiFi network, so I don’t know if that would work

So far I’ve tried 2 different Microsoft accounts (I made a whole new one because I didn’t know if it was a problem with my original account) and neither let me join

Hi, could be an issue with the wifi network itself. Due to its strange that this is happening with a different account.

Can you try this?
Disconnect your router from power for about 3 minutes. Then connect it again an when everything is working, try again

By the way, are you using a VPN service or similar in your iPad?
Are you not able to share mobile data using your phone and test in that way?