What is above your ceiling? Is there an upstairs? Is it attic space?

I had the same issue and it was the AC ducts that had lots of condensation. This happened after the furnace/ AC replacement.

Roof leak? What sort of structure?

Baby’s room is above the space, which has a heat pump register in it. We live in a two story cape.

How old is the roof? What is the condition of the roof? Roof flashings? Water can definitely show up far from the point of entry unfortunately.

I will cut the drywall and see what's there, you have to replace it anyways.

we had a similar situation and had many folks in to look before a two- part problem was discovered. Under the indoor portion of the heat pump in the attic was a tray to catch condensate....the outlet for the tray was partially blocked, so sometimes the tray would fill faster than it could empty, and there was a crack on the side of the tray, so the more it filled, the more it leaked. Quick and inexpensive fix, but took forever for someone to figure put. I was a northerner in Alabama, had never heard of a heat pump, so was no help at all.

That’s what we are thinking is the problem. Unfortunately the company that installed them has lost a lot of employees and heat pump install/service is in high demand up here in Maine! We have a different local (excellent) company doing our service so they are coming back out to take a look but I wish we could get a hold of the company that installed to come look. They are new, 2017 install, and we bought the house in 2018. We didn’t use this particular unit until this past summer when our son moved into his own room... then the problem developed... so I’m guessing it was an installation error. We shall see for sure this week!

Second what G W said above, plus have the tech check for both flaking rust on the actual evaporator coils (especially if it's a Lennox system) & the drain tube going from the coils' housing to the condensate pump. Our last house was a new build and the heat pump thankfully sat on the 1st floor slab foundation. Around year 7, we noticed problems starting with the A/C & would periodically find some water on the floor in front of the unit. After over a year of (bad) tech visits, one new good tech finally took off both panel doors (lower one was where the coils are) to inspect+clean everything (which should've been happening yearly he said), & discovered the coils were completely rusted. For years little flakes had been clogging the PVC drain tube to the condensate pump, then finally clogged the pump, too. He removed & blew out the drain & we had him install a new pump for all of $70. A year later bought a new heat pump unit, which was considerably more😕
Hope this isn't the issue with yours, but wanted to share just in case.

Focus on the HVAC system, pan under, etc.

*if your unit doesn't require a condensate pump, as you said it's on an upper floor (& may rely on gravity instead), I'd still recommend having the techs open the panel to look at+under the coils plus check the drain line for blockages. Our tech tested for a blockage by disconnecting the PVC drain pipe from the unit, then slowly pouring a some water down.

Thank you for all the advice! If the heat pump tech doesn’t confirm problem right away I will mention some of your tips!

Heat pumps here are always put outside, not in attics nor anywhere inside. I have never heard of a heat pump being put in an attic, but, since you are a much colder climate, maybe thats the reason.

It’s the inside part, that puts out heat and air to control the temperature of our home, that is dripping.