https://aviation-safety.net/wikibase/236372
Makes more sense what happened.
Having 100hp engine does you no favours when it's down on power.
Flap lever looks ok, but lights to show position could be missed in bright sunlight.
I think i would be in habit of looking over shoulder to check position.
Happened to me in a Cessna152, flap selector in correct position on touch and go but flaps didn't go up.
Fortunately it climbed 200 fpm on full flap, something i always practise pre solo with students.
Also good practise to fly full flap climb circuit to simulate power loss from a cracked engine cylinder.