When you first connect a new iPhone to wifi it does NOT have access to the network configurations from your previous phones.
For a hidden network ("Other...") you need to select the security type for that network (WEP, WPA, WPA2/WPA3, WPA 3, WPA Enterprise, WPA2 Enterprise, WPA3 Enterprise) as well as enter the correct password. If you keep getting "incorrect security type" errors it means you're making the wrong choice. You have to choose the right one.
If the error is "incorrect security type" this has nothing to do with the hardware. Replacing that iPad with another will accomplish nothing, so long as the OP keeps selecting the wrong security type - garbage in, garbage out.
Overall, though, yes, for setup it's much easier to connect to a different network - a "standard," non-hidden network (public or private). Once you're up and running you can ditz around with the hidden network until you get the settings right.