What is Teams bot's OptionFlags and how can one set its value?

Question

We deployed two policy-based recording bots A and B for Teams recording. However, only A can record. For bot B the call simply won't hit it. I checked ports used, and B has no issue in accepting incoming connections for the same ports used by A. I checked policies, the bots' compliance assignment, bot pairing as well as policies used by the caller and callee, but could not understand why B cannot receive incoming call. There is ONE difference between the 2 bots shown by command:

Get-CsOnlineUser -Identity {bot ID}

and the difference is the value of OptionFlags. The value of the working bot A is 128, while the non-working one is 0. I also created another set of two bots, deployed them and hooked the policies and users. The instances all started OK. However neither of the newly created two bots can receive calls and the values of their OptionFlags are all 0. I was wondering if the value 0 is the cause of the issue. I would be very grateful for explaining what OptionFlags's values mean, and how to set its value.

Dongning