I think the functional meaning is often alike or identical. And several comments address this.
It may be interesting to consider scenarios where the interpreted meaning changes in a clear way. ("Reading between the lines")
For example. If you are asked a question
"What did you do last night"
One answer might be:
"I worked until midnight and then went to bed"
Which is a direct answer to the question.
Another answer might be:
I was working until midnight and then went to bed.
Strictly speaking, in my view, this just states what you are planning to do, not necessarily what you actually did.
It is a defensive posture. I think this was pointed out in a comment. It can come across as lie.