Airport extreme not conecting to non-apple divices

Couple more questions. Just to help determine where the problem is..

Are you using long Apple wifi names with spaces and illegal (to windows world) characters like apostrophe?

Please change to short names, no spaces and pure alphanumerics.

Are your passwords also using mixture of characters not legal in windows world.. please make sure passwords and SSID names are identical on both airports only use mixed case and numbers. ie pure alphanumerics. This is stricter than required but fixes a lot of problems.

A screenshot from airport utility of the setup of the two airports will help.

As a general note.. A1301 is gen3 and very very out of date for modern equipment. A1408 is gen5 better but still well and truly out of date.

Easiest fix is just to replace your current Apple routers with standard mesh products like AC version Deco eg M5 or AX version would be more up to date Deco X20, X60 or X90... listed from most affordable to least. If your internet is slow.. say 200mbps or less then M5 are excellent value.

Let's start with what exact models are your AirPort Extreme base stations? How are they interconnected: by wireless or by Ethernet? Are all the devices that are not successfully connecting to a particular base station or to neither base station?

Were all of these devices connecting before? ... and finally, what version of Windows are the computers running?

There are lots of brands available in the mesh wifi market.

See https://dongknows.com/mesh-wi-fi-system-explained/

There is one aspect of the mesh systems I don't like.. which is the need to use cloud based service and phone app to setup and control your network.

It is well covered in this post.

https://dongknows.com/web-interface-vs-mobile-app/

He also has reviews of the various brands available and performance you can expect.

Unlike many network reviews he does use Apple products.. so at least is aware of the different issues.

Let me also state due to my dislike of Cloud based configuration I do not run typical mesh system with wifi backbone.

I use ethernet to various points in the house and Access Points (AP or WAP) which have some built in or computer based controller locally. Typical systems are Ubiquiti unifi and TP-Link Omada. I have used both and installed a couple of Omada systems for people. I refer to them as semi-pro type systems and do take a bit of learning.. so for standard home user without access to technical help I would go for domestic products like Asus or Synology. They are expensive for 2 or 3 node systems but fairly simple to setup and administer.

I keep looking for really cheap units to do the job. The Xiaomi AX1800 and AX3600 are my current toys. They work great but for the average user I would still say the setup is more complicated than it needs to be.

Feel free to post back if you have questions about any particular setup.