The president appeared to look off-camera for direction before his image was replaced with a graphic of the White House. His final comment was deleted from the video of the event posted to the White House YouTube page.
Biden has not held a solo press conference in the 42 days he has been president, breaking a 100-year record.
https://www.breitbart.com/politics/2021/03/03/wh-cuts-feed-joe-biden-asks-questions/
EDIT: Here is a good article about this moment of clarity from Biden.
Biden is very obviously dealing with dementia, at what point do the dems acknowledge it?