Right now you have two MX records published. One is for your root domain which is also an Orange clouded record. Cloudflare doesn’t proxy mail so instead returns a ‘fake’ Mx record entry for that record which is proxyable. Anyone who had the old record cached would fail trying to connect to that record and if their mail server is complaint should be failing over to your secondary Mx record (the one with the 20 value).
Depending on what that is and how it is is configured it may be delivering your mail to the mailbox or it may be in a store and forward mode to your primary mail record or … something else. You could create a new record (foo.yourdomain.com) as an A record and change that to be your A record with the same Ip address as your root domain if that is where you’re receiving mail if you’d prefer to have a set record for the primary.
It appears your 20 record is from a hosting provider (I assume yours) you might check with them as well for tips.