Is it normal? - 1.5 TSI revs up to 1300 rpm after staring

[Maxspecs]

Hi, I have little experience with petrol engines ...and wondering if this is normal...
When the manual 1.5 TSI (130) is started it immediately jumps to 1200-1300 rpms, sometimes goes up and down a bit a few times before gradually going down and finally settling down around 800-900 rpms. It takes over a minute before these stable idle revs are reached.
It is happening with both the cold engine or after a break of longer than 10 -20 min. All in warm weather, 20+ C outside.
When off and on but for only a few minutes it then starts smoothly at low revs of 800-900.
Any opinions?

Cheers!

(1.5 TSI 130 bhp, Sep20 build, filled up w/ E10)

[tos]

My 150hp eTSI DSG do it also at cold start. But it will slows down quickly.

[Crasher]

It is part of the catalyst fast light off strategy but something is amiss such as a dirty or misaligned throttle body, you need a code read first and the possibly the TB being cleaned and reset to the ECU.