Operational Challenges

I have an AnyCubic Kobra printer approximately 3 months old. I bought it new. After some new user challenges and some 3D learning I was able to print several PLA items. Using CURA slicer, I had worked my way up to resizing and minor modifications. I was comfortable enough with the unit and my capabilities that I was going to try simple PETG and TPU printing. Unfortunately before I had any opportunity, to experiment, my printer started acting weird. Without indication, it stopped sticking to the plate. I had this challenge and started to work through it, but then the filament stuck to the nozzle and would only curl upward. I replaced the nozzle but it does the same. I have tried temperature changes for both plate and filament but it does not work. I have tried adjusting tension for the filament but it does not change. I reset up CURA thinking it may be sending a wrong signal but nothing. My son (IT professional) has the same printer and can't see anything that changed in the settings.

I am hoping someone may have heard of a similar challenge and may have a solution or suggestion. I really liked what the printer could do when it was working and am disappointed that it had this hiccup.

Thank you for listening.

UPDATE:. With the information I was armed with from the assistance provided, I figured the problem was deeper than just settings. On a whim, I removed the nozzle and proceeded to clean out the element and this time pulled out a large 'chunk' of filament. It appears that it was restricting the feed but not completely blocking it. I cleaned the nozzle and inside a well as able and it is now printing. It still has a problem with filament strings and the odd 'blob' but it is much better. Thank you for your help.

Edit:spelling