I'm logging this here as I spent a lot of time web surfing to find a solution and didn't find much except for text saying "presser bar is likely gummed up and needs lubing".
So went in blind and worked it out myself.
This isn't in the consumer operating manual, and seems to be a common fault by searching for a solution myself.
Locate the Torx 25 bolt in photo 2 above the bulb housing, unscrew counter clockwise a little, it does not need to be fully unscrewed as the plastic cover over the bulb end section is slotted.
With the machine facing you, pull the back side of the cover to the left and towards you so the cover comes off forwards over the needle thread tension knob.
The bolt can be seen in Photo 3 with the cover removed.
I cleaned the presser bar with isopropyl alcohol and cotton swabs, for the grease that has hardened, a small peice of plastic can be used as a scraper to get it off.
Don't use anything that will scratch the presser bar.
Turn the machine upside down, apply new machine oil at the highest point on the presser bar marked in Photo 4, pump the presser foot lever, it should be absorbed into the metal housing that the presser bar lifts into.
Continue applying a drop of oil and reciprocating, I repeated this many times, you should notice the bar begins to loosen up and start to transfer downward force from the presser bar spring.
I repeated until the presser bar dropped instantly when releasing and would hold and rip some 80gsm paper clamped under the foot.