An instructor pilot reported landing gear collapse.

Narrative

The flight started like any other training flight; myself and my student arrived at the airport around XA:10 in the morning and after checking the weather and preflighting the airplane the engines were started by XA:35. Most of the flight was uneventful; we took off from runway XX at ZZZ; went south to the ZZZ Practice area; contacted ZZZ Approach and shot a VFR approach back into ZZZ (RNAV RWY XX). We then stayed in the traffic pattern to practice full-stop taxi back landings. We did three laps in the pattern for runway XX; Person A landings were smooth and the plane was performing and operating well and there had been no issues up to this point. We took off for one last lap in the pattern and after we had established a positive rate of climb and were building airspeed; Person A lifted the gear lever to raise the gear and the gear did not move; staying down. The gear motor circuit breaker had popped and after attempting to reset it; it immediately popped again. Person A took a picture of the mirror on the left engine cowling showing the nose gear fully extended and showed it to me; the gear horn was not sounding; and the transmission under the floorboard appeared to be fully forward; all indications that the gear is down and locked other than the motor breaker being popped and not receiving a green light next to the gear lever; so we continued to land believing the gear was down and locked. On touchdown; all three struts slowly collapsed causing the airplane to skid a short distance down the runway. I requested priority handling to tower; cut the mixture and we both exited the aircraft quickly. We were both unharmed and waited for airport operations to meet us and direct us further.I had been in the same situation (gear motor breaker popped; all other indications showing the gear was down and locked) in the exact same plane a couple months prior and we landed without incident; which may have created a bias in thought process throughout the situation.