Wife doesn’t even say good morning or hi to parents who are staying over

My parents are visiting us (from my home country, Pakistan) and staying with us for about 3 months in the UK. My wife (originally from South American country) actually invited them over as we haven’t seen them in a very long time (we got married during pandemic).

For first two days, wife was excited to have them, greeted them, took them for shopping when I wasn’t around. But lately, things have not been good. She talks to them when required. Sometimes not a single conversation the whole day.

But something that’s hard for me to digest is- not even a hi/good morning when they wake up and come to kitchen/living room space. Doesn’t even look at them. I do say good morning to both of them while sipping my coffee.

I brought this up early on and she said “they didn’t reply”. I ignored hoping they’ll figure things out. But now I see it everyday. I think even if you’re introvert, and not want to talk, or whatever- saying hi, acknowledging a human being- an elder human being- should be OK.

I know she’s overwhelmed having them over. They usually keep cooking in the kitchen for us. And maybe she feels that’s like invading the space.

How can I bring this up again with her? I don’t want it to turn to a fight.