I have fixed the issue. On the Github for the aircrack driver, it suggests to have NetworkManager set a fixed MAC address. Checking the Arch Linux wiki:
Note: Disabling MAC address randomization may be needed to get (stable) link connection and/or networks that restrict devices based on their MAC Address or have a limit network capacity.
I turned off MAC randomization for NetworkManager. I have a stable connection on both 2.4Ghz and 5Ghz networks consistently after rebooting several times, the latter network showing right after boot. Strangely enough, my network does not have filtering enabled. This wasn’t an issue on the ThinkPad with the dongle. Whatever the reason may be, it doesn’t warrant further investigation, I’m satisfied now.
Thank you all for your help.