Your students definitely shouldn't be losing points! There are a few reasons why this could appear to be the case, which we've outlined below.
The students are getting their Competition and Full-Year scores mixed up
Depending on whether you have a competition or your class selected, a different points total will be displayed. This could be the source of confusion, so we recommend confirming this isn't the case.
Points are being backlogged
During peak use (e.g. the Education Perfect World Series), things can start to slow down a little bit as our servers experience high volumes of traffic. In order to keep everything running smoothly, the points take slightly longer to update for users. When this happens, they are still being counted and stored, but the changes will take longer to display.
If neither of these are the case, please ask your students to send screenshots through to us at firstname.lastname@example.org along with their browser and device information. Any other information they may have of their Education Perfect activity leading up to the points loss is useful too, for example what topic they were working on.