Problem With Mobile Internet

Hello! I am writing to you here to share a problem I have had for several days and I hope one of you will be able to help me. A few days ago I was in Romania and there I handled my phone to see if I could start roaming. I found it where it is in the menu and when I pressed it it told me that it could charge me and I gave up. So far so good. But when I came home I turned on the mobile data because I didn't have wi-fi and wherever I went, in any application, site, etc. there was no Internet and it didn't charge. And at the top of the screen it says that there is 4G. Then I went into the settings to try to fix it in some way, but when I go to "Mobile data / Data connection / Mobile Internet" (or there as it is (there are different options)) I do not get the usual window where it shows how many megabytes you used, for what period of time,