Lost music file in flash drive and ssd with voluio 3

Hi I update to volumio 3 for 6 device 3 of them have error after pull out flash drive and plug in again (pi3 and pi4) can see volume of flash drive but show no flie in list. So I rescan and update data . Still cann’t see any file . I take out and recheck with PC all music in it has gone (also in ssd 500gb). Never found this problem before I use 3.179 version now change to 3,233 still test on it.