Have you tried a reboot? If not, try that first.
If that didn't help -- are you syncing Chrome with a Google account to multiple devices? If so, mismatched settings could be the issue.
Example. If you are syncing settings and passwords and your one source (perhaps a laptop) is syncing settings but does not permit saving passwords, that conflicts with your iPhone where you have allowed saving passwords. I had a devil of a time with bookmark syncing until I set all devices to sync everything. Now I can go from laptop to iPhone to desktop to Android device and everything is the same everywhere.