Sausage is splitting while smoking (in tropical countries)

[so_not_rad]

Hey guys,
Lets start by saying that I live in Thailand where the temperatures and humidity are extremely high.
I've been religiously making smoked sausages every week since I've been having a lot of free time due to Covid.
In the past couple weeks I have been having the same issue. I cure (24hrs) , grind, mix, and stuff the sausages, all at temps below 12C
Let them dry for 30 mins on so, and off they go into the smoker for another 40-1hr drying before I start smoking.
The smoker temperatures at the beginning are around 30/45C since its so freakin hot here, and the smoker is a stainless steel box
They look all fine, but I have been noticing that before I start smoking after the drying period, there is some micro sweating happening and its the fat.
Once I start smoking I start at same around 30/45C and gradually raise to 75C. After the first hour is when I notice that the fat has separated from the sausages and they split. It's not extreme splitting but there is a lot of fat escaping and it just drives me insane

heres a recipe i use
Pork 75%
Fat 25%
spices: fresh garlic, black pepper, marjoram, nutmeg 1-2%
milk powder 3%

The pork is salted +curing salt , ground and then I let it rest for 24hours, to help it cure.
The pork fat is frozen and I grind it straight from the freezer into the grinder.

Will take some pictures soon.
I could really use Your help.

I'm gonna go mad! I just can't seem to be able to make nice sausage without the fat splitting.
Any advice would be appreciated!

[redzed]

How much are you making at one time? What cuts of meat are you using? What is the percentage of fat in the "pork"? What type of fat are you using? What type of smoker do you have? Electric, gas, wood?What amount of salt are you using? And what type of casings are you using?

[so_not_rad]

How much are you making at one time? What cuts of meat are you using? What is the percentage of fat in the "pork"? What type of fat are you using? What type of smoker do you have? Electric, gas, wood?What amount of salt are you using? And what type of casings are you using?

Thanks so much for your reply Redzed.
I am making around 6-7kg batches total.
I'm using only pork shoulder - I break it down into pure lean cuts and all the rest that becomes fine grind which i use for "glue". The pork that comes has no fat on it. I use hard fat, or fatback as I've always have been. The smoker runs on gas, and I smoke with wood chips. Casings are always natural.
I'm starting to think that since its Rainy season here, the humidity has gone up by quite a lot. Could that be the reason?

[Butterbean]

I'm in a hot climate as well and don't have this problem so I don't think it has anything to do with your climate. My suspicion is you are stuffing your casings to tightly. If they are to tight to link easily then they are to tight which I found can cause them to burst. Either ease up on this or you could prick some holes in the casings to let some of the pressure escape but this is a PITA so I'd just ease up and give them room to swell.