Scheduling

I can't schedule any meetings for a day ahead or more from the PC app on my desktop.

I click on 'Schedule' and it brings me to a screen asking for attendees - then quite an awkward and fiddly start and end day and time drop down. If I put anything for the next day or beyond, the meeting just disappears once I press save.

This is a new problem as I was scheduling meetings last week! What's happened?