I have a mavic issue that started 3 months after purchase out of the blue. No sim card issues, I did all the research out there online but was not able to connect my mavic mini to the controller. Once in a blue moon it would connect for about 20 seconds and then lose connection again. The lights always blinked red and green from the start. I contacted DJI support and wanted to know how to resolve the issue. They told me to download the app and connect the device to check up on the firmware. It took me 2 hours of pluggin in the cable and trying to connect and eventually it found the mac. I started the latest update and guess what happened... It lost connection.

So the situation has gotten worse. On the battery indicator there are 2 leds constantly on (the most left and most right LED1 and LED4). I cannot turn the device off anymore other than pulling the battery. The other light is flashing RED and does nothing else. I cannot connect it to the assistant either.

What should I do?

Ask DJI to exchange your unit with a new one ... if they dont have mini they should give you SE

How old is the drone now?
Do you know anyone with a Mavic Mini that would allow you to try your drone with their controller, or your controller with their drone ditto the battery?
But if the drone is still under warranty I would be thinking about a return.
I think the SE is NOT available in Europe.

Its from August 23 2021.. can I apply for something like this? I don’t think I bought de DJI care package with it.

Assuming you bought it new in Spain from a retailer/shop than yes I think it should be covered by warranty and it sounds as if there is something wrong with it. See the likes of DJI Mindy's post  #17 in  the thread https://forum.dji.com/forum.php? ... D556%26typeid%3D556 .
Alternatively if you bought it from a shop then you could probably take it back to the shop, if you bought it from Amazon it may be worth contacting them, their faulty goods policy is very good (at least it is on the UK).
If you are a youngster then perhaps get a parent to deal with it. "can I apply for something like this? " makes me wonder about your age but DO NOT say how old you are, we do not need to know.

Thanks for your reply. I bought it in Croatia when I was on holiday. I still have the receipt, but I don’t know if I can get any support here in Spain. I will try calling Dji tomorrow. Thanks again for your help

I would be pleased to be wrong but in that case I think you will be out of luck.