Hi mummy! my baby had these too for a few weeks, pd mentioned that it's oil glands. i tried several methods and this helped.
Bathe my baby in 金银花, also used this water to wipe her face every morning and night. this helps to get rid of heat.
Sleep in aircon, 25 degrees.
Avoid using thick swaddles.
Used to shower in the day but changed shower time to before sleep.
The pd also prescribed sebclair cream.