Since the 11/6 update, parents and students are unable to log into the Mobile App when field level security to STU for the parent or student Portal Groups are are not given READ permissions. On an iOS, an error will occur when logging in. On an Android, the user will successfully log in but will not see any information. Programming is currently working on a fix for this issue and will be released ASAP.
UPDATE: A fix was released tonight for this issue, Web build 11/09/2020.
Has there been any recent issues? I have a few parents are our sites saying they are experiencing issues.
It's hard to determine the issue without looking at the data. Check the permissions according to this document to see if you have the proper permissions set for your parent/student portal group. This would impact parent logins or loading of certain pages.