Hi everyone, I recently switched to grapheneos and I cannot seem to be able to receive groupchat messages or activate RCS. Despite this, I can receive SMS messages normally and I am able to send MMS groupchat messages with the recipients being able to see my message. Here is some relevant information:
SMS app: Google Messages (no luck with stock SMS app either when it comes to receiving groupchat messages)
Carrier: Mint Mobile (using eSIM)
Phone: Pixel 9
GrapheneOS Build Number: 2026011301

The group chat I am testing with includes me (GOS) and three iPhone users. I previously used iPhone and was in the same groupchat before switching to GOS.
I have followed many troubleshooting steps:

Switching from stock messages app to Google Messages
Gave Google Messages app every permission (except location)
Followed this post's advice and made sure that Settings > Advanced > Group messaging > Send a single MMS to all recipients was selected in Google Messages
Deregistered number from iMessage (double checked this one as well)
Set APN according to Mint's FAQ
Regarding Mint's APN settings, I did notice that some of the fields they noted didn't seem to be available for me. Below is my current APN configuration.
Name: Mint
APN: Wholesale
Proxy: blank
Port: blank
Username: blank
Password: blank
Server: blank
APN type: default, mms, supl, ia
MMSC: http://wholesale.mmsmvno.com/mms/wapenc
MMS Proxy: blank
MMS port: 8080
Authentication type: blank
APN protocol: IPv4/IPv6
APN roaming protocol: IPv4/IPv6
Network type: Unspecified
---
The Mint FAQ mentioned the following settings which I did not find on my APN configuration: MCC, MNC, MVNO type, MVNO value.
I also tried using the http://mms.msg.eng.t-mobile.com/mms/wapenc MMSC (in that APN i also set the MMS port to be blank) to no avail.
Restarted device (did this each time I changed my APN)
Turned airplane mode on/off
Set GOS to only use LTE and not 5G
Followed steps on the Mint FAQ "Issue getting/sending MMS/SMS/RCS/iMessage (Android phones)" section
Followed the steps on this forum post

Despite all this, I cannot receive groupchat messages, and on Google Messages when I go to Messages settings > RCS chats my number is stuck on "Status: Connecting...". When I click on it, it displays "Status code: 3000" and "Status details: Please wait, activation is ongoing", no matter how long I wait. I also made sure after all these troubleshooting steps to wait for it to run the Next attempt to activate in which it still stayed stuck.

I checked google messages logs and even after all this I see: 01-22 02:20:22.110 15715 16016 I BugleSelfIdentity: Rcs is NOT_AVAILABLE for SelfIdentity. [CONTEXT sub_id=4 rcs_availability="10" ] which looks to say that RCS is not working (might be wrong here). The full log can be found here (this log was taken after doing all above troubleshooting steps)

Does anyone have any idea on what could possibly solve this / further troubleshooting steps? Are there more system logs I could look at somewhere to try and troubleshoot this? Forgive me if there is something obvious I am missing -- I am not very familiar with SMS/MMS/RCS stuff.