Java.io.IOException and connection time out how i can fix that

me and my friend we have been playing for a long time on the server from aternos but for 2 days it has been dropping us from the server: Java.io.IOException and connection time out .An existing connection was forcibly closed by the remote host
https://mclo.gs/0H1nIxs or https://mclo.gs/evjb7XO

we play on Projecrozonlite or Age of engineering
please help resolve this error

nope we live in Poland

pops up whether it .project ozone. vanilla. AoG

sometimes I connect to the server without any problem (vanilla)
sometimes i can connect after the 4th attempt (modpack)
and my friend is not so lucky. he can not join the server at all

yes and that dont work :{

we changed the crystal launcher to technic launcher and everything works fine, but it probably crystal has a login problem

because it is universal