Can you share a specific example of where this has happened (with evidence that pricing was lower for someone else who hasn’t searched for it?). I’ve seen lots of speculation that carriers are ‘personalizing’ prices, but no actual evidence to support it.

UA was doing some dynamic price thing where they sometimes price directly on website into a class with zero inventory. For example, I’ve seen instances where it will give me an ‘S’ fare when T9 S0. But never heard of that increasing pricing just for me - when I see something like S9 L9 K9 and it prices me into S, it’s because there is no fare filed in L or K.

The one thing I have seen close to what the OP is talking about is when I at one point noticed awards when searching in morning resulted in a lower price, then it increased in the afternoon, then back down next morning. This was several days in a row. Several years ago, also. Not really sure what that was about, but haven’t seen it since.