Bottle strike and decrease food intake

I am starting to get a little anxious.....
I started working full time a month ago.....at first things were fine
and DS was taking 2 bottles of ebm a day plus solids.......then a week
ago he started a bottle strike.....he is not taking much ebm during
the day and he is not eating as much solids as I would hope....
DH is doing his best to keep him fed through the day with little meals
but I don't think it's helping....
DS nurses right before I leave and right after I get home and a couple
of times through the night. He is almost 11 months old and up until a
month ago he was 23 pounds but he looks like he is losing weight....
Is this normal for babies who transition from fully breasfed to
bottlefed ebm??

FayeC