Moderator, if this is in the wrong forum, fell free to move it

I live in a retirement village, which has a set number of ethernet outlets ,which all centre on a patch panel cabinet.

In this cabinet is the chorus box connected to fibre and a Netcomm NF18ACV router provided by my ISP (Now Broadband). Wi-Fi is a bit sketchy in the study, which is the furthest room from the router, so I installed an Edimax EW-7478APC AC1200 in the study as an Access Point. I set the AP as the main Wi-Fi on 2.4 and 5Ghz and the router as Guest access on 2.4 and 5Ghz. The other advantage is that there is only one ethernet outlet in the study, so the AP provides additional ethernet outlets. 

The AP in the study is fed directly from the router via the patch panel and ethernet cable. Note that the instructions for the Edimax said that when used as an AP, the WAN outlet is not used.

In the study I have a Desktop PC, which connects to the AP via ethernet cable. I also want to be able to use a laptop in the study at times when my wife is using the PC and at those times I need to access the data files on the PC.

Now to my problem. The laptop cannot see the PC and vice versa.
It worked at my previous house.

When I look at the network status on the PC, it says it is connected to Ethernet 2
The network status on the Laptop says it is connected to XXX 2.4G 2 (where XXX is the name of the Wi-Fi network).

Both devices are set to Private network and I have turned on Network Discovery on both devices.
Both devices have the same password to logon.

What am I doing wrong please?

Thanks