Arrow count does not decrease, unable to choose which arrow to use either (no soul arrow being used).
Usually the arrow that's used is the one highlighted on your use slot, and i think it happens only if you're with a bow/xbow equipped. Maybe the arrow that's being used is way down on your use inventory... also i haven't heard of this, so it might be a bug indeed... ????
Check to make sure you have the following in the correct order: 1. You have a bow/crossbow equipped. 2. You have the correct arrow for bow in your inventory (there are arrow for bow and crossbow, make sure you have the correct type) 3. When you have multiple type of arrows, the chosen arrow will be highlighted in blue box and will always be the most top left corner in priority order. 4. Make sure bow is firing, bow whacking will not consume arrow. If none still works, try to record a video of what happened so the staffs can have a better look what happened.