Wifi issue when sim card off

[jesselayng_jl]

Hey i have a ZenFone 3 ultra and when a travel i need to turn off my sim card. unfortunately when i do that it seems to affect my wifi connection. It has limited signal on strong networks and drops signal constantly. Seems to work fine when sim card is on.
Now i have looked through the settings and there seems like limited access for network settings. Is there anyway to better diagnose the issue and try to correct it