iPad safari says its in private mode?


Today I have had 3 students have issues with 2 specific websites, where the website says it cant load because safari is in private mode. We have a configuration in place to disable private mode and filter content. Before today this issue was not brought to us. Chrome works fine for both websites. Devices were at iOS 11.4 and 11.4.1 and none have updated recently. They did not return the issue when i un-scoped the config file, but its odd that others are working just fine. Wondering if anyone else has seen this.