check FFS running in batchfile fails

[lupatico]

I've several FFS batchjobs running from within a bat-file (win8.)
I tried all options in Windowds Tasklist and Find options to check if any FFS-job is still running. If so continuing to the next step waits for 20 secs and then test again.
No matter which syntax I use, batch file responds in a split second that FFS is ready, while it is still running!! These are my batch file lnes:

Echo Start batch backup Thunderbird and DATA folder
start /MIN D:\Sync_Thunderbird.ffs_batch
start /MIN D:\Sync_DATA.ffs_batch

:Label_3
rem Echo Label 3
rem Echo Test FreeFileSync still running
rem If no, continue, if Yes wait via Label4.
tasklist /nh /fi "STATUS eq running" | find /i "FreeFileSync_x64.exe" && (goto Label_4) || (goto Label_5)

Has anyone any suggestions how to tackle this?