Can't delete contacts from SIM card
I should have waited a bit more. But maybe this helps someone else with the problem. I had just had to restart, load the app, see it still detected no contacts, leave the app, go on another app, wait a bit, and get back to Contacts app. Then it showed the problematic contacts. And I was able to delete them, only from the Contacts app.
And I think the problem is really from the apps that put duplicates --&gt; Whatsapp, MBWAY, Google account, any other account on the system that synchronizes contacts. It creates duplicates and the phone got everything mixed up. Not sure if it's my fault or those apps' fault in mixing the contacts. I just wanted only the SIM contacts on the entire phone... But no.... The apps have to put the contacts of their own there. Cool. Thanks a lot. Amazing... But at least it's fixed. I deleted all the contacts and put them back one by one. Now I'll install the apps back and put my account and see what happens...