Linked mailbox not receiving mail if No Internet Access shown even though connected

Question

Since the past few months, our linked mailbox started showing no connection to Exchange when the network status shows "no internet access", even though we are connected and still able to surf to other sites. It is just Outlook that is unable to "connect".

We are using Outlook 2016 on-prem with linked mailbox.

Understand that some apps like Outlook rely on NCSI to detect network connectivity and the status would sometimes show as "no internet access" if the passive probe is used. If we switch to active probe, status will change to "internet access" and the linked mailbox will be able to connect to Exchange.

We also tried the same on Outlook 2019 with another Exchange, but without linked mailbox, and even though network status shows "no internet access", Outlook is still able to get connected to Exchange.

So we're wondering if there could have been some updates in the past few months that caused this change in how Outlook 2016 determines internet access or could it have been due to some settings in Exchange? Any advice would be greatly appreciated! Thanks!