but it worked until the HVAC service showed up.
Did you attempt to prompt it further into figuring out the actual problem, or know what they did to actually fix it? My bet is on a bad starting capacitor for the motor --- something that's a relatively cheap and quick repair.
I installed 4 mini splits with it two years ago and they are still working great and blowing ice cold air.
It walked me through measuring refrigerant, subcool and superheat, pulling the vacuum, brazing the lines, exactly what tools to buy, I even input the numbers from the meter and it told me how much to add and so on. And this was with GPT4 or something far less intelligent.
In the past I tried to learn this stuff but the HVAC community are massive gatekeepers and try to hide information behind paywalls or spread FUD even though anyone could do it with the right tools and a little bit of knowledge.