KB746 – Input Lag

My KB746 ("Dell Pro 7 Wireless Rechargeable Compact Keyboard") has a noticeable input lag when any modifier key is held down. It is present both when connected via USB receiver and via Bluetooth. Over Bluetooth it is significantly worse as characters are either input in the wrong order or not at all when any modifier is held down (obviously most noticeable with Shift).

I suspect a firmware issue (assuming I do not have a defective unit) as it persists on multiple devices (Windows, iOS, macOS). This kind of issue does not present on my devices with any other wireless keyboards I have tested, including another Dell keyboard (KB700).

(I previously posted this issue in another section of the forum before realising this area may be more appropriate.)