By following suggestions in this forum (basically, by deleting USB data), I managed to charge my s9 plus again. However, although there is no check port notification anymore, still there is the check port icon. How do I get rid of this?
I revert to my previous question, which is not an issue anymore. I realized that the icon I was complaining about was is in fact a battery status icon, following the mid mode set by me. It is OK now. Sorry for the inconvenience.