Query on Fedora's mirrors

Greeting to the lovely Fedora community, how are you all doing? I'm James. I has been my pleasure using Fedora server as my server of choice but since recently - almost two weeks now, I have been trying to upgrade my server and I have been experiencing some errors (mismatch md5sum) with the mirror that is automatically selected by dnf. I've searched for alternative mirrors via Fedora's wiki pages as well as other source but I am not finding relevant information. I've done the necessary troubleshooting such clearing all dnf cache and restarting the server but the issues still persists. Are there any viable solutions to this issue like probably switch to a main mirror or other mirrors of choice or obtaining the necessary gpg keys for validation? And if this is possible how can I navigate particular mirrors. Another question as well, it seems as if gpgcheck in dnf.conf is by default set to False, doesn't this create some vulnerablities? Feel free to respond at your convenience and your response would be greatly appreciated in advanced. Thank your for your time and consideration. Best regards, J. Williams