Is it "normal" for a prepaid account to lose data service on renewal night?

[fetcher]

I'm on the grandfathered $30/mo 5GB+100min+unlimited-text "Walmart" plan, which is a great fit for my use pattern. My account was scheduled to renew for another the month last Saturday night / Sunday morning, and I'd received the usual automated text advising of this two days prior.

I happened to be out very late that night, and had been using the phone off and on, but just before 3am I found that data connections were suddenly failing from any app, despite having a good LTE signal, while voice (including VoLTE) and SMS continued to work. I didn't try MMS.

Soon after, I noticed two icons at the top of my screen that I'd never seen before (see 1st image) - a "!" mark on top of the LTE signal-strength indication, like what shows atop the Wifi icon when there's no usable Internet connectivity, and also notification to the left with a "?" on top of similar signal-strength bars, analogous to the "Log Into Wifi" notice Android gives when behind a captive portal on public Wifi.

Pulling down my notifications showed a "Log Into T-Mobile" entry attached to that question-mark icon, and selecting it brought me to the intercept page shown in the second screenshot. In case that image doesn't come through, it read as follows:

"Current Plan Status

You currently do not have data service.

If you want to access the internet and your current plan does not include data, you must change to a plan with data.

If your current plan includes limited data, your data bucket has been depleted.

To obtain data service, you can:
- Renew early if your plan allows
- Upgrade to a plan with data or a plan with more data."

This was puzzling, given I had used well under 1GB of my 5GB allotment from the previous month, and had a $60 on my account, enough to cover two months of service. I also had a credit card on file for autopay as a backup, though I usually fund the account separately to avoid their service fee.

After getting home, I logged into my T-mobile account from a computer, and at first got a "System Outage" message (attached), making me think this might be some widespread problem affecting many customers - did anyone else happen to notice trouble around 3am Eastern?

Trying again, after 5-10 minutes, I was able to log in, but one information box said "We're temporarily unable to access your account information", and the other stated "Refill required", despite noting my $60 balance.

I went to bed, woke up Sunday morning to find the phone's data service working normally again.

This got me wondering, though, if the early-AM data outage was just a one-time fluke, or if this is something I can expect to have happen on renewal night. Is it "normal" for there to a multi-hour window between one month's prepaid service closing out and the next month being established? This may have been the first time I happened to try using it at that time of night on rollover day. Maybe I should start carrying my backup phone on that day?

If it was a temporary suspension of service, though, I'm still puzzled at why only data was affected, with voice calls and SMS continuing to work.

[AnciusD]

I'm on the same Walmart plan. I've noticed 3am East Coast, is when the plan normally resets but I've never lost data connection, though I've never tried to use it at that time either. Occasionally, I've tried the short code #932# to check if it's turned over and get the message that it's not available but that's it.

[fetcher]

I'll try to remember to test this next month, maybe leaving a tethered connection up overnight on the expected rollover date, with a VPN connection routed through, or maybe just a slow ping running to check afterwards for any connectivity outage.

Hopefully it was just a one-time glitch, as suggested by the website wonkiness around that same time.