Look for a login item that’s mounting a network share, as a starting point. System Preferences > Users & Groups > select your user > Login Items. Look for a volume in the list.
Hmmm, no chance of connecting to 192.168.64.anything there, do you have any other connections, like Ethernet, etc.?
With Subnet Mask of 255.255.255.0 you can only connect to 192.168.1.anything IPs.
IP arcana...
While it’s fairly rare for smaller office and smaller home networks to have multiple subnets, it’s entirely possible to have multiple subnets, and it’s sometimes entirely necessary.
If there’s a router here and as there often is, then connections across subnets can and do work just fine.
In this case, 192.168.1.1 is probably the ISP router, and some of those routers can connect across local subnets.
I’ve also encountered folks with mixed wired and wireless networks, and those can involve multiple subnets when the wireless network is not configured as an access point (bridged) configuration; the Wi-Fi network uses a router, and a non-bridged Wi-Fi network normally uses a separate subnet from what the ISP router is using.