bpm flickering on right side rekordbox with ddj400

Need a bit more info please.

DDJ-400 Firmware – CHANGE HISTORY
ver. 1.03 (9 March, 2021 Update)
[FIXED]
 Minor issues have been fixed.
ver. 1.01 (17 September, 2019 Update)
[IMPROVED]
 Improved TEMPO slider stability.

↑Why don't you try UPDATE?