XPS 15 9570, U2725QE, low wattage power adapter error via 140 W TB4 port

With my U2725QE monitor connected to my XPS 9570 laptop via the 140 W TB4 port (and with no other peripherals connected to the monitor), I get the lower wattage power adaptor error on startup and through the Dell Power Manager ("you have attached an undersized adapter to your system"), even though the laptop adapter is rated at 130 W.

Firstly, why is this showing up and, secondly, can I just ignore it? The laptop charges ok with this connection, with no apparent effect on performance.