When scrolling back in “My Calendar” on the web app, entries are shown twice in weeks that include the first day of a month (see the screenshot below). This occurs on macOS in both Safari and Chrome, and only affects entries that were not visible prior to scrolling.
Interestingly, if I switch to another browser tab and then return to the Trainer Day page, the duplicate entries disappear. However, they reappear after reloading the page and scrolling back again.