Some problems after update ios 15.1

Before the update there were no problems about using any applications, after update when i start twitter it closes itself first time and program runs after i start it second time, and it shows me the latest tweet, before update it had showed to me the last tweet which i didnt see before, and i have a big problem about another application after update 15.1 at Zborsa which is an application about stock market, titles which i saved are deleted everyday, and i need to add them everyday again. I really dont like that if apple change its principle as windows that updates occur new problems.