Internet out, but network connections fine

Are you using a VPN possibly? Sounds like a possible DNS issue. If you can ping google, use the IP address and put that in the address bar of the browser. If that opens to the site, then you know it's DNS related. Alternatively you could try it in Safemode to see if resolving domain names works properly.

Start up your Mac in safe mode - Apple Support

Shareef Yousef wrote:

Same subnets. It’s a corporate VPN, but has always worked while connected via wired and wireless. The issue only occurs rarely after waking from sleep.

Same subnet depends on the router doing the correct thing; being transparent to the routing. Different subnets would be typical.

This could be a VPN bug, an IP routing issue, an IP routing issue with the VPN, or a macOS bug.

Do things work better when one network connection exists, and not two?

You’re also going to need to do some digging around preferred routes and related, and whether that VPN is set to route all traffic, or just some of it.

Shareef Yousef wrote:

This is definitely not on the routing (external to the computer) end as a computer restart resolves the issue. Additionally, as mentioned, I can successfully ping various sites.

Routing is still in play.

As for it being VPN, my local network is 192.168.10.0/23 and the vpn I use is split tunnel and only routes 10.2.0.0/16 and 10.4.0.0/16 networks. I'll have to keep it in mind to try seeing if disabling the VPN would fix the issue the next time it happens, but again, considering it only routes 10.x networks (ie, private only), can I can't see how that's an issue in getting pages to load in the browser.

VPNs are based on IP routing.

You have routes for the VPN, and routes for each network connection.

And what might not be obvious at first, there is no correlation between the route used outbound and the route used to return. This can mean that packets can reach the destination, but response packets can get dropped on the way back.

One other thought I had is that a local web server loaded in the browser during that issue. This got me wondering, do browsers use alternate DNS servers for resolution/caching?

There is no alternate DNS, there is IP routing.

Apple has two DNS implementations, traditional DNS and multicast DNS, and both integrated into macOS.

Where things get interesting with DNS on macOS, some command line tools bypass the local DNS caching. Browsers and such, typically not. Command line tools can byoass, though.

If IP routing is messed up, there will usually be connectivity issues.

And if there are DNS issues, you’ll usually get timeouts and errors. A thirty second pause in activities tends to be a bad DNS server (a DNS server translation timeout), for instance.

I really don’t like finding two controllers in the same subnet, either. That makes things ambiguous.

Are the wired and wireless connections using the same or different IP subnets? Different IP subnets would be typical, but maybe your router deals with this case itself.

First-few-hops VPNs are solving a problem that hasn’t existed for a while, and are not something I’d recommend. This differentiated from a VPN connecting into a remote internal network; a network for an organization you are affiliated with.