No voicemail notifications on wifi, mobile data always on

Roblmay79

I hope I didn't just spam this question but I don't think it posted the first time. Apologies if I did.

When wifi is connected, the voicemail tab of my phone app shows an error message saying it can't sync with voicemail and prompts me to call customer service, error 9004.

So here's my situation after lots of troubleshooting and talking to a few customer service reps:

• Using Moto G Stylus 5G
• Mobile data is always on, I never turn it off
• Can only receive voicemail notifications and download voicemails when wifi is off
• Using default Android Phone app with the "voicemail" tab, there is no other voicemail/visual voicemail app on my phone
• Battery set to unrestricted by default for the phone app without options to change that, turned off adaptive battery for good measure
• Can place/receive calls (including to *86 for voicemail) and text messages when wifi is on
• Have tried settings, system, reset, reset wifi mobile & bluetooth several times but it doesn't resolve the issue
• Have tried clearing all data for phone app and reinstalling, then reactivating "visual voicemail" in the phone app
• Can only receive voicemail notifications and use visual voicemail when wifi is disconnected

It seems that wifi connection blocks mobile data without blocking cell service (can see signal bars but no 4G LTE/5G). If this is the issue I haven't found a way to solve it. Have yet to try troubleshooting on a different WLAN to see if that would make any difference.

Is there anything I'm missing that I should try? Thanks in advance!

Roblmay79

Thank you for the replies, though I failed to update that I managed to fix it.

After ensuring that background data was unrestricted I completely reset the phone app to factory default and cleared all the cache and storage for it and restarted the phone, and that seemed to make it work right again. However it took trying this method several times in various orders and it took my whole Wedneaday, so I'm not totally sure what did the trick.

The matter of fact is that by all accounts I've read, the phone needs access to the cellular network and I'm led to believe that it may need mobile data connection, however so long as data is on the phone should still be able to receive voicemail notifications while connected to wi-fi. I'm also led to believe this is a very common problem with Motorola and Samsung phones, which makes it weird that it seems to be difficult to find solutions to it.