Hello once again! Since I cannot edit old Lemmy posts, here's an update on my two posts: Issue with NetworkManager and Internet Connection Issue #2.
For the first post, the issue has not reoccurred where NetworkManager would ask for my password almost every day since a NetworkManager update that happened sometime between now and 2 weeks ago (I don't remember exact day).
For the second post, the problem of the stalling internet connection over VPN is most likely with the ProtonVPN Linux app. Someone recommended that I use the VPN via OpenVPN and so far, that has worked without flaw. I have since uninstalled the app and do not plan to use it anymore.
Thanks for all the helpful replies and I hope someone might find my posts useful sometime in the future!