@kozmikpetukh I would have needed to subscribe to roaming with my carrier, and probably should have as a backup to Holafly.
In the UK, the phone operators don’t charge you for receiving text messages while abroad and this does not require paying for a special roaming package. I have to pay for making calls and sending texts abroad, but receiving texts is free. According to Google, this is also generally true for phone companies in other countries as well.
From the sounds of it you are from the US (when you referred to T-Mobile I originally thought you were talking about the Russian T-Mobile! But I suppose you meant the US one.) This is what the US T-Mobile say on their wesbite: “If you’re in a destination where international roaming is not included with your plan or international pass, you can still use calling and messaging services but data is turned off by default.”
With my phone operator, I can pay for roaming (to use mobile internet) on a day-by-day basis, which is what I did for a couple of days in Russia. This roaming worked fine for the limited purposes I required during those two days, e.g. logging into Gosuslugi while at the bank. (From the looks of it, the US T-Mobile is similar: its one-day passes cost $10).
I never tried to use an eSIM. But from your experience, they sound problematic. I do not understand at all why MTS kept your eSIM blocked even after 24 hours. Sounds like a big mix-up between Holafly and MTS. Registering with Gosuslugi is necessary to get a Russian SIM but that’s a completely separate issue from lifting the 24-hour block.
@kozmikpetukh And, the SMS block seems roaming-independent - I’m still unable to receive texts from t-bank for example. Even back in my domestic network.
As mentioned, I personally have had no problems receiving SMS messages from T-Bank on my UK phone number. But it is notable over recent months that a lot of different types of messages from Russia do not get through. E.g. I have been unable to receive SMS messages from mail.ru and Yandex, and phone calls from Ozon also have stopped reaching my UK phone number.
This is apparently because Western telcos are increasingly blocking communications from Russia (assuming they are malicious or spam). Not clear why they let messages from some Russian companies get through but block others.
So perhaps you have been unlucky with the T-Bank messages. A couple of suggestions that may help. First of all, when I recently downloaded and activated the T-Bank app, T-Bank stopped sending the codes by SMS and instead sent them as app pop-ups. So have you checked to see whether messages you expected to get from T-Bank by SMS have not instead been sent via the app?
Even if you cannot find any history of app messages from T-Bank, it ought to be possible to adjust the app settings to enable it to display these messages (cutting out the need for SMS codes entirely). I realise that in Russia you only had intermittent access to the internet, but it should still be possible to catch up on messages sent to the T-Bank app when you have access to Wifi (e.g. at your hotel).