Iphone SE backup problems

My last backup went through iTunes just fine on 11/25/24. When I try to use iTunes to backup to my PC, I use the Manually Back Up and Restore feature. Today, the Back Up Now button is not highlighted and hence not available. The same is true if I try to use iCloud (which I don't use anyway). My iTunes software is up to date with 18.1.1, the iPhone SE is updated with 18.1.1. I switched USB cables. I tried different USB ports. iTunes can see the iPhone on the PC, it can be manually sync'd without any errors. The PC can see the iPhone through the File Explorer. I have disabled BitDefender to see if that would help, something I never have done before, it doesn't have an effect on the problem. I have used IMazing software to extract data from the iPhone SE backups without any problem, there was nothing wrong with the backup of 11/25/24. Is it possible that the latest IOS update has interfered with my backup procedure?