One of my coworkers has a habit of "tuning me out" while I am talking. This involves completely ignoring me and working on something else.
This has happened before the requirements to work from home. In the office at their computer after a hour or so of going through our codebase together, they would just switch to a different tab and start looking at the stock market. At first I was really confused and asked them what they were doing, and they would say they didn't understand what I was explaining, become slightly defensive, and then would continue looking at stocks.
My response to this in person would usually be just to say "I guess that's all... just tell me if you have any questions", and then to go back to my desk.
However, since working from home, they tune me out more often, and after a considerably shorter amount of time. Recently after only 15 minutes of talking about code they switched to a different window and starting working on something else. They were sharing their screen at the time, and we were talking about the code on they screen, so this completely stopped the discussion. I asked them why they switched windows, and they said they didn't understand what I was explaining, and became very defensive.
This would be fine, except this same coworker calls me almost every day to ask questions about our codebase. I contribute the lion's share of code to our codebase, so it isn't unreasonable to frequently ask me questions, but the level of disrespect they are showing is making me dread accepting their calls.
I'm worried they feel like ignoring people who are in the middle of talking is acceptable behavior, that they are becoming more brazen about doing it, and that they are becoming increasingly defensive in trying to justify their behavior.
I've never experienced anything like this before, so I'm not sure how to respond appropriately. Any help would be greatly appreciated!
I've tried asking them to tell me when they're confused, or have a question, or if anything doesn't make sense. When I do this they become very defensive and often say something along the lines of "everything doesn't make sense", or "I didn't understand anything you said".
I have also tried getting them more engaged in the conversation, but this too seems to cause them to become defensive and just generally say they wish they were working on a with a different language or with a different framework.