ios16.1 Wifi issues

Check your WiFi Router / Modem for --> Recommended settings for Wi-Fi routers and access points ...

Connecting to Wifi is the first part and then getting connected to the Internet is the second

1. If you connect to Wifi, doesn't necessarily mean you are connected to the internet. If you are not connected to wifi could be a problem with iPhone settings or Router/Modem Settings
2. If you are not connected to the internet is the sole issue of Router / Modem Settings. Contact your ISP immediately

For your Internet connection.

• Over Cellular: contact your Carrier (Cellular Service Provider). The agency who issued the SIM to you
• Over WiFI: Contact your ISP (Internet Service Provider), the agency who provided the Internet Service on your Modem/Router to you

However --> Connect iPhone to the Internet - Apple Support

You have not made it clear whether it is WiFi connectivity or Internet connectivity is issue that you are facing.

Many users who have updated to iOS 16 and above must have a similar issue if the issues stated by you is due to the iOS.

Unless you state what the issue is many in this forum may not be able to respond positively to the issue you are facing. 

With the limited information that you have provided, It is hard to even guess the problems faced by you. 

You may get faster and better responses to your query by --> Writing an effective Apple Support Commun… - Apple ...

Please re-post with detail so that someone else can help.

I have also been a victim on my iphone 13 after the upgrade to 16.1. The Apple support confirmed that it had nothing to do with the upgrade.

I tried the following solution and it has worked.

https://www.gadgetbridge.com/how-to/how-to-fix-ios-16-1-bug-that-randomly-drops-wifi/