starter problems vs dough/temp problems vs malted flour problems

I have been using my 100% starter for several years now, and have , until the last 2 months, had consistent, desired results when I followed my regular recipe and method. 

Here how I make my bread:

Ingredients

110 grams 100% starter

308 grams room temp water

550 grams flour

1 scant teaspoon salt

Directions:

1. Dissolve starter in water
2. Add flour and mix either by hand or in mixer with dough hook until just mixed. (It is ok if a little of the flour is still dry. It should not look like a nice dough yet, should still be a shaggy mess. )
3. Let the dough sit for 20 minutes.
4. Add the salt and mix thoroughly.
5. Knead for about 6 minutes in mixer or by hand until the dough makes a nice , slightly sticky ball. ( I usually do about 3 minutes in the mixer, then turn out into my counter and do a slap and fold type kneading, but really any old kneading works, whatever you are comfortable with)
6. Form dough into a ball, and place in an oiled bowl , cover with either a dishtowel or plastic wrap. (I use those shower cap looking bowl covers)
7. Place bowl in a warm place , such as the oven with only the light turned on, and let rise for about 2 hours. It should have risen slightly, but most likely will not be doubled.( Sometimes I can only tell it has risen because it deflates when I remove it from the bowl.)
8. Turn dough out onto counter and gently pat the dough out into a rough rectangle. Fold the dough into thirds  first in the long direction, then again in the short direction.
9. Flip the dough over, and gently stretch it out again into a slightly smaller, thicker rectangle. Roll the dough up from the short side, tucking the ends in slightly, and place roll in a a greased bread pan. Cover the pan with the plastic wrap and place pan in the refrigerator for 8-24 hours.
10. Remove pan from the refrigerator, and place in a warm spot (the oven with the light on is again a good choice) remove plastic wrap and cover with a moist dish towel. Let warm and slightly rise for about 2 hours. (IF it is very warm, and the bread starts to rise bake it sooner, or you will loose the oven spring.  )Again, the dough may night appear to rise at all, that is ok, as long as your starter is good, you will get a nice oven spring and the bread will still be tasty.
11. As it gets close to the two hour mark,  preheat for at least 10 full minutes at 450 degrees.
12. Make a quick slash in the dough , cover the bread pan with another bread pan of equal size, and bake in preheated oven for 30 minutes.
13. Remove the top bread pan and continue baking at 450 for 20 minutes.
14. Remove bread from pan immediately and allow to cool on a wire rack.

I do not feed my started until the night before I plan on baking (or the morning), when I remove from the fridge, feed it a 1:1:1 , then use it as it is going down. 

Shortly before Christmas, I started using an organic malted AP flour that I was purchasing from Costco because it was so much less expensive than the smaller bags of organic AP flour I had been purchasing. That flour was not malted. 

About 2 months ago, I noticed that when the started was fed, instead of being thick, as it has always been, it was thinner, and by the time it was going down, was downright runny. It also had a slightly more acetone smell to it. The dough never would rise as nice as it had before, though it did rise in the oven, but not to the size it had been. The test and texture appear to be close to the same, not exactly, but definitely not bad tasting and totally edible. 

I have always used the plain AP flour for feeding, so I decided to give it a boost by feeding some whole wheat flour. I LOVED the whole wheat flour, and was nice and bubbly, but when I used that starter with the AP flour for bread baking, the same thing happened. , the dough did not rise. 

I am waiting for a new batch of flour to arrive, plain organic AP flour, non malted, to see if that changes anything. I did make a couple loaves using einkorn- unfortunately, I did not read the bag that said to reduce water by 20% when using for bread making, and made it a bit too wet. It tastes ok, but the texture is a bit gummy. It is nice toasted though. 

So, is there a problem with my starter( which, after being infused with the whole wheat flour for feeding is bubbly , happy, and nice and thick again), or is it the malted flour which is somehow making a difference? I have not noticed any issues in using this flour with my other baking adventures (cakes, cookies, etc). 

TIA for any help, input you all have. 

Sandy