NAS visible to only some computers on network

I’m unable to access my Synology NAS drive from three computers on our home network. I cannot tell if the problem lies with the Synology NAS, our router, or the computers in question.

Here is the relevant information:

– Synology NAS is connected to an Orbi Satellite, which communicates with the main Orbi Router (RBR50). The home router address is 10.0.0.1, and the drive is 10.0.0.26 (IP is reserved for it).

– All devices on the network can connect to the NAS apart from these three computers.

– The three computers that cannot see the NAS cannot even ping it at all. Synology Assistant will not find it. HOWEVER: find.synology.com will locate it when run on these machines. They will then be unable to connect to it. It’s like any connection to the drive is being completely blocked on these machines.

– The problem began quite recently, but I cannot say why. I thought the cause might be an MacOS upgrade to something like Ventura 13.3.5 (a), but that only happened on two of the affected machines. The third is very old and running an older version of OSX.

Is it possible that the Orbi router is somehow blocking just these devices from connecting to the NAS? Why would that be?