BUG! All Day Event

Hello, there seems a big bug if you create a all day event. I was create a all day event via webmail. For exymple All Day Event 31.01.2023 - 31.01.2023 . After Save all was perfect. Now if I want change that topic of event I chnage this but All Day Event now from 31.01.2023 - 01.02.2023. That strange you can see on webmail even while edit. Sure you can change that date manually but if you add a new all day event or edit a existing all day event by outlook, iphone or another device you will get that issue that it autoatic save 31.01.2023 - 01.02.2023 because there you cant change this… could anyone tell how solve that bug?