Perhaps you had just changed the battery or a fuse when this started?
Not sure if anyone will read this, but this same exact problem was happening with me after I had changed a fuse and I found something that fixed it. Not sure if it would work for you, but it's at least worth checking.
When I opened the back of my meter to change the fuse, a rotary plate that is supposed to couple with the rotary switch got bumped out of place. To check and see if this is your problem, follow this:
-remove the 4 screws and remove the back of your fluke 179
-remove the single screw under the 440 mma fuse that holds the board in place (mine was a #1 philips)
-The rotary switch coupled with another rotary part on the board, and under the board was a small, white plate that was coupled to the intermediate rotary part. It is about 5/8" in diameter. It's the part that rotates with the rotary switch and makes the contacts for whichever function you are using. It has two tiny springs on it that make contact with the board.
-That little rotary plate has a notch in the edge that fits into a key that holds it in place. Mine had 'jumped' out of it's resting place with the notch in the key. I simply put it back in place, put it back together, and it was running like new.
Hope it helps! Peace!