so its definitely the case of either the driver missing in the 4.7.13 update, or a glitch.
As explained before, it's not a RetroPie issue - but a regression in the Linux kernel as shipped with Raspbery Pi OS. I think this issue is similar to your problem or [this forum topic]*https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=246587).
copied the driver file 8188eu-5.4.72-v8-1356.tar.gz to the boot section, extracted it to its own directory, installed..and BOOM..everything works a charm now
That's good, except that you'll get the same problem if/when you upgrade your system and the kernel version will be upgraded - currently is at 5.10.17. Keep an eye on http://downloads.fars-robotics.net/wifi-drivers/8188eu-drivers/ if you intend to upgrade, it looks like the drivers are updated and kept in-sync with the Linux kernel included in Raspberry Pi OS.