Someone has turned on TCP state logging which is not enabled by default. This feature was mentioned in my Max Power 2020 book, pages 319-322. See sk101221: TCP state logging
Looks to me like in your case the TCP state updates are not being properly tacked on to the existing log entry; I would speculate that perhaps you only have session logging enabled for the rule matching this connection, but not connection logging which is I imagine where the TCP state updates will need to go. For the difference between the two see my 2022 CPX speech Max Gander: The Hidden World of Log Generation and...
Attend my online "Be your Own TAC: Part Deux" CheckMates event
March 27th with sessions for both the EMEA and Americas time zones