Hi
@Odin004 - as others have mentioned, both type 1s and type 2s eating a low carb or very low carb can and do experience what's known as "physiological insulin resistance" after a period of low carbing, which is a mechanism whereby the GLUT4 transporters in the cells are effectively turned off to allow any glucose produced to be used by the brain first (as the brain is the main organ that has a minimum requirement for glucose, no others do). In terms of T1, as most of the exogenous insulin we take is taken up by muscles rather than the liver (very little injected insulin makes it to the liver), having fewer active GLUT4s means that we don't process insulin as effectively. This also means that glucose production from the liver is less likely to be reduced.
Metformin works by decreasing the glucose production of the liver in response to both protein and to the natural requirements, while alcohol achieves the same thing because the liver is single tracked and can't produce glucose whilst processing alcol. That demonstrates one mechanism for dealing with physiological insulin resistance.
When I have been low carb, I have also done it in combination with resistance training, which depletes glycogen stores from the muscles and liver. This has the secondary effect of re-enabling GLUT4s in the muscles as they try to replenish those glycogen stores, meaning that they are there when exogenous insulin is applied, and I haven't, therefore, experienced an increase in insulin resistance.This is also a mechanism used in the "body transformation" world, where a low carb diet in combination with a resistance training programme is used to cut body fat and maintain low insulin requirements in non-diabetics.
In order to try and handle what you are seeing, it may be as simple as hitting the gym for weights sessions two or three times a week. What I've measured in terms of insulin sensitivity, when not low carb, is that for the 36 hours after a weight training session, my insulin sensitivity increases by up to 30%, so it's certainly something worth taking a look at as a way of dealing with it. Hope that helps.