Ford focus 2000 - all doors unlocked, but none will open

wagon

#1

Greetings,
It’s been a cold winter in Michigan, but things are warming up this week. Just in the past couple of days, I’ve noticed that when I unlock my car doors, they still won’t open. I thought maybe they were frozen, but the temperature outside is mid 30’s (much warmer than it has been the past week or so). I try locking & unlocking the doors again (& again), still nothing. This has happened 3 times now, the first time, one of the doors finally opened after about 3 minutes, the 2nd time, they finally opened after about 7 minutes, but this 3rd time, I even left the doors UNLOCKED when I went inside, but I came back to find that even in the unlocked position, they still wouldn’t open - nothing opened for about 30 minutes, and then when one of the doors did finally open, it was the back trunk door which doesn’t usually work with a key. I climbed in through the back & was able to open the doors from the inside, no problem.

Thoughts? Advice?
It’d be much appreciated!