Dear Lastpass Team, what's wrong with you that you can't answer this question? We are paying for this service....
I have the same issue. I have LastPass Families subscription. Lodged a Support ticket and went back and forth with the rep who appeared to be pretty clueless on what and why the 'Site Search' Alt+W feature is, asking me to try this and that and "report back". I did all those to no avail, and throughout the ordeal I mentioned a couple times this should be relayed to the developers team - that the 'Site Search' shortcut is extensively used. The final response from the rep was asking me to provide a screenrecording of attemtps to hit the shortcut key Alt+W to log the issues so the team can look into it. That shouldn't be my job - I report an issue, provided the information regarding the operating system I use and what not - it's YOUR job to diagnose by trying to replicate the issue then proceed to find a solution for the customer. I found it utter ridiculous that I did not spend more of my time to get around a screenrecording (for Lastpass to sit on it) and the Support ticket was eventually closed. Disappointing service. Seriously what's wrong with you Lastpass?