They are not the same couple.
As I understand the research, both Matthew Fullers were present in Barnstable in the same timeframe. The non-Mayflower Matthew was son of John Fuller.
Internet lore shows a Matthew Fuller marrying Frances Hyde/Lyde/Idye, but I haven't found any sources that show his marriage. I can only find sources of Mayflower-line Matthew Fuller marrying Frances _______.
TAG 61:194-199 is a well-reasoned, sourced article on the two different Matthews.