Wet upper bedroom closet wall behind insulation

Hopefully this complicated story will make sense...

We have a 25 year old two story brick home. We noticed a musty smell in our walkin master bedroom closet. This closet makes up the north east corner of our room. That room was always cold even though there is a heating vent in it.

We removed the drywall and vapour barrier and also cut open the hardwood and subfloor along the northern outer wall. We suspected that maybe the kitchen exhaust fan vent which runs up into the bulk head and directly under that closet to vent outside, was causing condensation and the smell. The exhaust pipe was poorly insulated but no real mould issues near it. The corner of the floor had some mouldy spots on subfloor and underside hardwood along the edge. Removed affected wood and treated the remaining areas.

Long story short...It seems the problem was with the eavestrough. No downspout on that corner. A few days before the last rain storm we patched a couple of holes in other areas of the eaves that were leaking....the eaves were going to be replaced in the spring. The old troughs were warped toward that north east corner and water collected there and spilled over during heavy rain. We notice the very wet closet walls right after that rain... we did have just insulation up on the walls at that time during our repairs. We took it down again.

Eaves are now scheduled to be replaced but in the meantime a hole was cut to allow water to drain down into barrel and drain away from foundation. Once the hole in the trough was made we didn't notice any further wet spots on the closet walls...even during rain storm.

The weather was getting much colder (below freezing at night) so we thought we should put up the new insulation. We didn't want to finish the walls so that we could check again when the eaves were replaced and a new downspout was installed. We didn't install vapour barrier yet...mistake.

Insulation has been up for a week and this morning we noticed that when we pulled the batts away from the wall, the wall was wet/frosty. There was no rain ... just some light snow last night but it was very cold. We removed it all and are running a dehumidifier... walls dry now.

My questions..finally....

Are the wet walls caused by the fact that there was no vapour barrier up over the insulation and house is warm but outside freezing?

Should we reinstall the insulation and vapour barrier once walls are dried out? Or are there other things we should be checking?

I should state that there is no ceiling damage. Ceiling was taken down and replaced initially when we thought maybe a roof leak was happening to cause that smell in the closet. When we originally had opened the walls, even during rain we didn't see wetness come in so we thought maybe it had been from the ceiling...(water probably not leaking in because the eaves patching had not yet been done and the water didn't collect in that corner).

We had a leak from chimney in the guest room that caused a similar smell so thought this was a repeat. The roof is only about 10 years old has high end shingles...no leaks visible from inside looking up at roof and no ceiling drywall damage when we removed it. No damage evident from attic inspection.

Any advice / confirmation of what we are thinking is the wet/frosty wall cause is very much appreciated.

Thanks,

Diane