If the soft delete was enabled for your ACR , those images will still be occupying the space in the ACR. Space will be reclaimed only after the retention period. (i.e., while enabling the soft delete you might have mentioned the retention period as 7 or 14) . So soft deleted images will be removed only after that retention period and corresponding space will be reclaimed !!
I just tested locally on my ACR with Soft Delete Enabled and with out Soft Deleted Enabled. If the soft delete is not enabled , when I delete the image space got reclaimed immediately !
Let us know if you have any follow-up questions !!
Regards,
Shiva.