Monstera Thai Constellation help!!!!

[raaain5outh]

I need help so background info

• Shipped from Thailand with long healthy roots and already had the damaged areas on leaves prior to shipping
• Repotted with mix of mostly cactus mix then miracle-gro, plant charcoal for base, and general all purpose soil in 10" ceramic pot with terracota bottom
• Just recently watered yesterday with soil being dried to second line of finger when stuck in
• Just recently placed slow release fertilizer sticks during recent watering
• Warm Humidifier is on 12 hours
• Moved towards the window in the picture now but was previously in my room with plant lights
• Located in Portland OR, Not a lot of bright sun most of the time and mostly cold

So seen in the picture my monstera has been slowly turning brown at the edges and where there were holes have turn brown tho I have trimmed them they are slowly browning again. There is a new leaf growing but has not grown since I had it (been a month now). There is 2 smaller ones that are doing fine except one of the plants is forming a brown dry spot in the middle of the leaf. There is also these brown bark like spots on the stems. I used diluted dawn yesterday to wipe down the plant with a microfiber to try and see if the spots came off and no luck. They don't appear to be bugs as I managed to scrape one off and it's the actual plant. It's not soft or anything just dry

 

[raaain5outh]

I'd like to add that this new window does have bright mostly indirect light just the picture now is sun setting and the room is a lot warmer around the 60's + humidifier warms up the room as well. My room that it was previously in was smaller and had the humidifier to keep the room warmer but the window didn't give much indirect lighting for long so it was mostly under a plant light that was place indirectly a few feet away from it for a month til yesterday

 

[OpieDoodle]

A few things could be causing this but most often it comes down to a watering issue.

1. How often are you watering?

2. How are you watering? (like do you super saturate until it drips out the bottom, just a little bit, etc)

3. When was the last time you repotted it?