The message
from The Natural Philosopher contains these words:

Could be you have a marginal situation house-wide anyway.

Try switching on a 3KW fan heater plugged in the same place.

also check for neutral earth shorts on the drier, or elsewhere.

Or if you're feeling foolhardy and brave, open the plug and disconnect
the earth wire to see if it still does it.

--
Skipweasel
Pay no attention to that man behind the curtain.