Burning bootloader without external clock, result is... off.

I got the Minicore bootloader to burn as well, sadly I am still having issues with not being able to upload sketches to them. The blinking pattern has changed however. It is now bliniking rapidly 3 times, on reset, but then turns off for one second, then blinks rapidly again, and repeats.

Is it continously rebooting? Why?

I left the bootloader burn setting to default with the exceptios of setting it to use the internal 8mhz clock. Anything else I need to do?

This is my exact steps at the moment:

1: Upload ArduinoISP to my uno, using the UNO board and AVRISP mkII setting.

2: Disconnect the board while I hook everything up.

3: I hook up the non-bootloaded atmega to the uno.

4: Change the programmer to Arduino as ISP and board to the Atmega328 "board" and set it to use the 8mzh internal.

  1. Burn the bootloader. It reports burning successfully (as far as I can tell).

  2. Replace the uno atmega with my new bootloaded atmega.

  3. Upload a sketch with 1. settings

  4. Get a timeout error.

What have I missed? Since it's possible to burn to the MCUs at all, I am guessing they aren't busted and I am making a mistake somewhere?

Edit: Got a hold of some 16mhz crystals and tried the external clock setup. Sadly, I get the same issue.
Since it's possible to