IPhone 12 does not connect to hotspot

Dear support,

my IPhone12 with iOS 18.7 refuses to connect to a hotspot from a NVIDIA Jetson Orin device. All other devices like Android phone, Laptop or even iPAD (iPadOS 18.7) does connect to the hotspot without problem.

Hotspot runs on 2.4GHz/channel 11 with WPA2 (no internet connection)

When trying to connect (SSID is shown in Wi-Fi setup) it simply says either "Unable to join the network "xxxx" ""

After I reset network and when I try again is says:

This network is operating on Wi-Fi channels in use by several other nearby networks. Restarting your wireless router may allow it to automatically choose the best channel to use, and may resolve this problem.

Restarting the hotspot doesn't fix the problem. When I check the other networks none is operating on channel 11. So, warning isn't really helping. How can I resolve issue, are there some hotspot settings whoich need to be in place to allow iPhone to connect. Please help/advice.

Many thanks in advance for your support