Rekordbox not import all tracks in playlist

Hello friends ! I have a problem that no one solved it until now. I am rx2 user and I noticed that I don't have all my tracks imported in playlist. as an example my commerical folder have 872 tracks but rekordbox only import 502 also I have no error when importing and analyzing. As formats I habe Mp3 / wav / flacs. Please help. Second problem is when I use rekordbox on windows pc If I minimize windows and open any explorer tab I have output sound lag. Pc specs msi g65 win 11 i7 10750H nvme ssd 16gb ram and gtx 1660ti