The simulation, that can be downloaded below, shows a couple of CMOS Schmitt oscillators consuming more than 20mA peak. As the RC networks use 1Meg resistors the only place this current can be flowing is the device supply current. In fact whenever the output of either gate is low, the device consumes 20mA. Surely this is much more than would be expected?
https://www.dropbox.com/scl/fi/yk0clhjwut9bmj0n77ahg/Cloakroom_lamp_warning.qsch?rlkey=wdgb4a9y9fgxaow8oh8j6f4d1&dl=0