Mails & folders aren't pusch from eM Client to the mail server (mail server change)

eM Client Version: 9.2.1735. Backup was done with the same Version. In case I can provide the log file
Hi all, hereunder the situation
I’ve migrate my website and therefore I did it also for my mail server (Roundcube). Before migration I did a backup. So to start, I’ve set al the new credential in the my eM Client (eMC). So far so good, When eMC start to synchronize all the folders and data just disappeared. Every time I get the data lost I had to upload them in the eMC with the original backup.
IMAP credential was not a problem BUT SMTP credential was always wrong. He took always the former password (the one before the migration) even if I’ve created a new account
I tried hours to find a solution but no way.
Finally I’ve create a new mail account on the mail server and create it on my eMC. At that time I could create both side mails and folder. So far so good. My target was, on the eMC, to copy folders & mails from my original account to the new created one. No way, by moving mails, the system wanted always connect my original account to the server but if I let him connect, then all folders & mails in the original account would disappear
I’m asking help from the community because at this point I don’t know how to proceed
Thank you in advance
Eric