Windows Update no longer checks for updates in Windows 7 Ultimate

This problem began a few months ago and it this point it is becoming annoying. I run Windows 7 Ultimate in a virtual machine (VMware Fusion) on an iMac (Retina 5K 2014). The Win7 VM was built from an image of the Dell Studio XPS I had in the office up until the motherboard died—the VM is recognized as a Dell Studio XPS 435T in the System control panel—and, excepting a few Fusion quirks from time-to-time, my Windows 7 VM has always worked just as it did on the Dell hardware from the time I got the iMac in February 2015.

At some point last fall, I noticed that I was not getting the regular Windows update messages that I was typically getting roughly every week. I explicitly have my settings in Windows update set to,

Check for updates but let me choose whether to download and install them

So at the very least I should be getting notified that updates are available. After several weeks of not getting notifications, I manually checked Windows Update one morning to find that I had an excessive number of updates awaiting to be downloaded, so I spent the better part of a wasted workday downloading and installing several weeks of updates. I checked my update settings, which had not changed, but Windows Update still does not check for and notify me of new updates for my Windows installation as it should. What gives?

FYI: I am running Windows 7 Ultimate Service Pack 1 (64-bit) with 8 GB RAM dedicated to the VM in Fusion 8.1.0 on an iMac 5K (2014 model) with OS X 10.11.3 with 32GB RAM.