@mshepus 

have you activated the guest network on wifi

  @MR.S  Not on the network that the printer is on. Should I try checking it?

I did (previously) try to create a second network with guest network checked to try to create network people could use without a password, but that one doesn't show up in available networks by any devices.  (did I mention I'm a newbie?) ;) That's another question I have.

  @mshepus 

yes you said you were a newbie :-)

but if you are a newbie you should start with the documentation, here is most of what you need to know before you start with a company's network solution...

I can't help you with a simple answer when there are so many parameters. but from the description you have of the problem, it says that the wireless device is isolated and does not talk to each other. on Omada, as far as I know, only the guest function does this on wifi or if you have activated ACL on WiFi or switch, you can also do it there...

If you have ACL switched on, try and disable this.

I am attaching a link to the documentation so you can read a bit, here you will find answers on how to configure.

https://static.tp-link.com/upload/manual/2024/202405/20240517/1910013634_Omada%20SDN%20Controller_User%20Guide_REV5.14.pdf

If you take a screenshot of the SSID settings, I can see how you have configured it

It should look something like this in the settings

Thank you  @MR.S !

I'm offsite today, but will check those settings and also send you a screenshot tomorrow.

Cheers!