Why can't data information be displayed on the computer after punching in? No record?

Lz's central attendance machine Our company also uses it. We studied together and found the following rules:

1, the screen display and voice confirm that the punch-in is successful, but there is still a phenomenon of missing records after downloading the records;

2. This phenomenon mostly occurs during the rush hour;

3. This phenomenon mostly happens after the previous person who punched in successfully, and the latter person punched in after the screen has not returned to the clock state, and the screen and voice were also confirmed to be successful. At this point, the record will be lost from the downloaded record.

Suggestion:

The effective interval between front and back punching (actually a few seconds);