I checked again, and I found something "strange" the waveform on the oscilloscope looks good, but the led (red) does not lit.
I used 10k and 1nF for both CV and CC.
Initially the led was flashing rapidly, now it does not lit. And when I connect the load, the voltage drops from 26V to about 0.7V.
If I remove the 1k emitter resistor and replace it with a wire, then it works normally, but it oscillates.
I also tried with 10k + 10nF in CV but it also oscillates.
Later Edit: I tested with 10uF in parallel with 33uF on the output, and with 10k + 1nF for both CV and CC, and I got the attached screenshots, with the PSU shorter, with 0R load resistor.
1. Output at about 12V: 0725.jpg
2. Output at about 26V: 0726.jpg