I am using jdbcsql with a mysql 5.1.43 server in an B4A app with no problems. I already have a running mysql 8.0.25 in my dev machine, so I did some tests. I tested connecting my B4A app to that server without changing anything. This is what I had to do to make it work:
See
https://stackoverflow.com/questions...n-type-from-standard-to-caching-sha2-password
I used this:
ALTER USER 'root'@'localhost' IDENTIFIED BY 'password' PASSWORD EXPIRE NEVER; ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '{NewPassword}';
And everything works fine, without having to change anything in the B4A app except the mysql server port (just because I have mysql 5 on port 3306 and mysql 8 on port 3308)
Adjust the SQL command to the required username and password. You will probably want to remove the "@'localhost'" part to connect from other hosts.
Of course this means you are using legacy authentication, but I am sure you understand all that.