I don't like many sudden unplanned meetings appearing during your estimated development hours. It consumes some development time and destroys your momentum.

We follow the 2 weeks sprint that contains sprint ceremonies like sprint planning, demo, retro, daily stand ups and backlog grooming meetings. My capacity should be less then 80 hours since there are sprint ceremonies and unplanned meetings that happen during development hours. Unfortunately, my capacity is still set to 80 hours and meetings hours are not deducted. This puts me to a disadvantage as I need to do unpaid OT/weekend work just to make up for the lost time consumed by meetings.

Those 1 hour/30 minutes meeting piles up thus consuming development work hours. So a simple example is that you have 32 hours estimated to finish a big user story but sudden unplanned meetings and sprint ceremony meetings will consume some of that 32 hours. I will bring this up in our next retrospective meeting.