iPhone 17 Pro: MMS setting missing from Messages

I have an iPhone 17 pro. Changed a few service provider because I was unable to set up MMS. It is completely missing from the message setting screen. Problem persisted despite doing network reset, switching iMessage on and off, reinstalling eSIM etc. Service providers checked their ends and unable to come up with solution. When eSIM initially set up, MMS is present. But once my old number was ported, MMS option disappeared. I still have the normal voice line and data.