previously reported on old forums (see links below), kaspersky kids blocks google classroom and gmail - the two sites that kids these days need most. Turning off safe kids solves the problem. This is a subscription ending problem unless resolved.
First thread below indicates a bug was found but my son gets ERR_SSL_VERSION_INTERFERENCE whenever going to gmail.com or classroom.google.com. Occasionally, it will magically work, but he is getting it today for hours.
I happened to be home - after much digging, i can see nothing that should prevent it. After turning off safe kids and successfully going to gmail.com, now it does work (in 2 diff browsers) with kids turned on! Unfortunately, the same trick did not work for classroom.google.com.
https://forum.kaspersky.com/index.php?/topic/402418-kaspersky-safe-kids-blocks-google-classrooms
https://forum.kaspersky.com/index.php?/topic/408252-when-safe-kids-is-enabled-gmail-hangs-when-trying-load/
some of the google sites that are required, that i referenced in the first link, require wildcards or have multiple numbered variations. There is no way to effectively enter those in the allowed list, perhaps that might also be related?