ODK Public Access Link Requiring Log-in

I have a form which is made available via public access link. This public access link works fine in the UK but when passed on to my South African colleagues requires them to log-in to ODK (as shown in the screenshot below).

I have ensured the form state is Open , single submission if No and have checked how it performs on incognito browsers in the UK (it works as intended).

I need help in how to make this form accessible to my colleagues. Why is it requiring log-in in the first place and furthermore should I create a universal account for these colleagues to sign into so they can fill out the form?

Is it possible that some characters were lost when opening up the URL? Maybe it was truncated in an email or something like that?

Have you seen this happen to more than one user? What browser are they using?