Thanks for your answer. Here is my comments on this.
It's not always the iOS update's fault! Many things can cause phone problems. If you tell people you think it's an iOS update, it might make it harder to fix or find a solution for the real issue.
This is the only thing that have changed so that’s why I point on the update. I could be wrong but the new update made it worse. It’s very unstable and maybe I can’t compare a connection with a iPad that have a better antenna. I am getting a WiFi repeater next month so maybe that will solve my issues.

Remember, the right question often leads to the solution!
I am not sure what you mean by this. I did my best explaining how and what is wrong.

Was/Is your device Jailbroken? If that's the situation, please be informed that attributing the issues to iOS updates may not be accurate.
No it’s not jailbroken and have never been. Didn’t even think it was possible on new Iphones.

Kindly consider checking your settings and addressing any device issues before attributing the issue to external factors. This could be a pure coincidence that the iOS update affected the iPhone functions.
My settings have not changed since last update. Side note: I use the official silicone cover with Magsafe.
Before initiating a standard iOS update, it's advisable to create a backup. Have you completed this step? If yes, proceed with the restoration from the backup.
I only backup my phone data in iCloud, and that happens automatically.