the development temperature is 40.1 degrees C instead of 41.1, maybe because of that?
No, that won't result in uneven development.
I found this formula in a book
The formula isn't entirely as per Kodak's literature. See here, page 30 in the pdf (numbered page 7-28): https://www.kodak.com/content/produ...ssing-KODAK-Motion-Picture-Films-Module-7.pdf
The main deviation is the different amount of bicarbonate. Again, it's a relatively small difference and it won't result in the defect you report here. There are some other, smaller differences, but I don't think they would have any effect at all.
Yes, I'm sure, I did not stir it much, and I don't know why I left it so unstirred. Is that the cause of the problem?
That's possible, yes. I'd try another roll and agitate continuously, or at least every 30 seconds (but preferably continuously).