Hi @Esteban_Meneses1386,
Thanks for reaching out, and I totally get how confusing it can be when basic functionality suddenly stops working. It sounds like the bounding box might be hidden. That would explain why you're unable to resize or rotate objects from the corners.
Please try going to the View menu and selecting "Show Bounding Box" if it's currently hidden. That should bring back the corner handles for resizing and rotating.
If that doesn't help, kindly let me know which version of Illustrator and operating system you're using, and whether this happens with a specific file or all files. Also, if possible, share a short screen recording demonstrating the workflow for better understanding.
Looking forward to your update.
Abhishek