I am developing a project with a standalone atmega328p, and in order to program it, I'm using an Arduino Uno as ISP Programmer:
I generally work with Platformio, but I was troubleshooting something so I used Arduino IDE (1.8.19) to test something.
I use Arduino IDE to upload the ArduinoISP example on the UNO, it works without an issue.
However, next thing I do is to test it by uploading Blink to the atmega328p, so in Arduino IDE I select "Arduino as ISP" as the programmer, I click on "upload", but the sketch is uploaded to the UNO, instead of using the UNO as a programmer for the standalone atmega328p.
This is a Arduino IDE issue because when I use Platformio I CAN use Arduino as ISP without a problem.