Error message "Server authentication problem (401)" seen while trying to submit data collected through Enketo

Hi again!
I aksed the survey users to change their account seetings as adviced the previous days, in order for them to have view access of their data and control for unwanted submissions.

Now they try to submit their draft forms and they have the 401 error

They use safari as a borwser, would this be an issue? how can they solve the problem? what if they change the account settings again - not requiring authentication- will they be able to submit? and if yes wiil they be able to view their forms throught the “open” icon?

thank you!