Inventory checking output overrides stronger redstone signals

When a comparator is pulling a signal from a block with in inventory, but simultaneously also receiving a redstone signal, it will not always output the correct signal strength (pulling a signal from a block with in inventory seems to override the other signal even if it is lower).

What I expected to happen: a comparator pulling a signal out of a chest (with only 1 item) through a solid block, but this block is also powered by another comparator with quite a strong signal. Normally a comparator outputs with a strength of the highest input, therefore equal to the signal inputted by the other comparator.

What actually happened: the comparator outputs a signal strength corresponding to the amount of items in the chest, so a signal strength of one.