EPI Dog cant firm it's stools With tylosin

Hello,

my marley is a year and a half castrated malinois. 6 months ago it was diagnosed with EPI after the TLI test came positive (diagnosed by a vet). since then the dog cant keep firm stools regularly even with 30g of enzymes a day (from enzyme diane).it's stools has yellowish tone. he is taking tylosin for the past 5 weeks and Nothing. we have tried all kinds of dry kibble food and currently on Veterinary Royal Canine Gastro Intestinal - low fat. still nothing.
recently he began to pee in his sleeping area and in general cant hold it's water.

currently weigh 22kg and its target weigh is 27kg

my question is - can it be more the EPI? something the vet missed?