Tanning issue

Hello and good day
I put 4 limed hides in my tanning tub last night used 1 10L bucket of water with a brain and put it in the tanning tub. I come on this morning i have 1 leather and 3 limed hides 98% to 99% done .. I know before when i used just 1 bucked of 10L water and a brain it tanned all 4 hides .. this a bug due to update? or working as intended?
I put 4 limed hides in my tanning tub last night used 1 10L bucket of water with a brain and put it in the tanning tub. I come on this morning i have 1 leather and 3 limed hides 98% to 99% done .. I know before when i used just 1 bucked of 10L water and a brain it tanned all 4 hides .. this a bug due to update? or working as intended?