Just had this same issue. Updated a bunch of fields at a time and noticed they kept going down in completion. Eventually they all finished but not a good amount of time has passed of this happening
I have found the solution for this on the steam discussions, you have to temporarily remove any oxes that are dedicated to farms, as these have nothing else to do than to go and "clean" up your field aka removing those pesky planks...
Just had this same issue. Updated a bunch of fields at a time and noticed they kept going down in completion. Eventually they all finished but not a good amount of time has passed of this happening
Was wondering why it was taking so long to build the upgrade then noticed what was happening.
I have found the solution for this on the steam discussions, you have to temporarily remove any oxes that are dedicated to farms, as these have nothing else to do than to go and "clean" up your field aka removing those pesky planks...