Calendar gone bonkers

After iOS 15.1 my calendar has issues. The current day is no longer high lighted, it’s Monday right now and Saturday & Sunday are high lighted. Also, if I want to change a day or hour for an appointment the “Day & Hour” tabs on my iPhone 12 are clear at the top left in a darkened bar where the current time is located. They can not be accessed, number one they are overwritten by the current time and I get no response if I tap on them. I have to delete the appointment and reenter it if I need to make a scheduling change. Please advise if you have a solution for this issue. See the two attached screenshots.

I noticed they were many issues with Calendar after 15.1, is this due to time constraints and lack of testing?? I was mainframe COBOL programer for many years, my employment would have been much shorter for letting something like the above slip through to production.