I strongly suspect that Biden does know that Trump took classified material to Mar-a-Lago.

This was reported a few weeks after Biden took office:
"President Joe Biden doesn't believe former President Donald Trump should receive classified intelligence briefings, as is tradition for past presidents, citing Trump's "erratic behavior unrelated to the insurrection."

When asked in an interview with "CBS Evening News" anchor Norah O'Donnell if he thought Trump should receive an intelligence briefing if he requested one, Biden said, "I think not."
"I'd rather not speculate out loud," Biden said when asked what he fears could happen if Trump continued to receive the briefings. "I just think that there is no need for him to have the -- the intelligence briefings. What value is giving him an intelligence briefing? What impact does he have at all, other than the fact he might slip and say something?""

Biden and the entire intelligence community knew Trump was a security threat. I imagine he would have received a briefing to that effect when he took office with the details. But, to avoid the appearance of going after a political rival, he took an arm's length approach to letting Garland manage everything. I would be more concerned if Biden did know the raid was occurring.