sed leaving temporary files behind

[da]

Hi,I'm using gnu win32 ver 4.2.1 of sed.When using -i option, sed always leaves 
behind temporary files named sed* in the directory where it's being called. 
(ie. NOT in the directory where the edited file resides.)Each successful run 
leaves 1 temp file behind.
When I supply a file extension using -itmp, the expected file backup gets 
created in the directory where the edited file resides. The temporary files are 
still left over in the execution directory.
>dir sed*
 Directory of C:\GitHub\merlin-etl\merlinDBScripts\dbChanges\sql\prod
File Not Found
>sed -i "s/ad/asdf/" \temp\1.csv
>dir sed*
 Directory of C:\GitHub\merlin-etl\merlinDBScripts\dbChanges\sql\prod
22. 02. 2022  10:28                47 sedhJDLA6               1 File(s)         
    47 bytes               0 Dir(s)  173 949 931 520 bytes free

Thank you,Daniel Adam