Why do mailbox names change?

Question

PHP

Good afternoon!
I have a PHP script for working with mail via the IMAP protocol.
Sometimes the case in the name of mailboxes changes.
Example:
{imap.gmail.com:993/ssl/novalidate-cert}[Gmail]/All Mail
or maybe
{imap.gmail.com:993/ssl/novalidate-cert}[Gmail]/All

mail works. Because the mailbox name is case sensitive.
Another mailbox has gibberish: [Gmail]/&BBIEQQRP- &BD8EPgRHBEIEMA- (this is [Gmail]/All Mail)

Guys, maybe someone knows: why does the name of the mailbox change?
Thank you!