coal speed increase now random or a bug?

[Whyamihere]

I planted 4 new fields and replanted 1 existing field. On the 4 new fields I put down 10 wood chips and then 1 coal. On 2 of the fields it gave me a 7% speed increase on the other 2 it gave me a 5% increase. On the existing field I put in 3 lime then 1 wood chip then the coal and it gave me a 6% speed increase. According to the wiki on the existing field being the 5th fertilizer that one should have been an 11% not 6% and why would it be lower than 2 of the others which the coal was the 11 fertilizer. Anyone else seeing anything like this happening or did I miss a patch note about it or something.

[Whyamihere]

Have tried using coal several more times and it has acted correctly for me ever time since. So either I was mistaken and had put more down than I thought or it was a one time glitch.

[JohnCarver]

Thank you for following up on this. We were unable to replicate the error as well.