If i try to connect to a world that is on my device, and have an internet conection it shows:

Unable to connect to world. Please check your connection to the internet and try again.

(I seen this glitch on my phone[Huawei Y6 prime 2018, Stock firmware], and on our old tablet [Asus memopad 7, Linage OS], also on [Xiaomi redmi 7a, Stock firmware] this gltch doesn't happen)

I am connected to the internet

And also i found if i have the wifi turned off that i can join, and if i mess around with the wifi(turn it off, wait until it shows Generating world, then turn it on) i get insane lag wich is probably due to minecraft trying to contact my phone thru the router (I know this from my limited programming skills)

Can you please look into this issue.