Different colour casts across my print

Hi, Just wondering if anyone can tell me whats happening to my prints?

My problem is, I will make a well colour balanced print, then make another copy afterwards with the same settings and the print can have a red cast in part of the print: example in photo 1


or the print can have 2 colour casts in it, where its Red in the middle of the print and Cyan to the left: example in photo 2


or just part of the print will be Cyan: example in photo 3. The top right of print is Cyan



I am using a Durst rcp 20 roller transport machine with the temperature at around 24 C because the Dev bath takes over 3 minutes and over 3 minutes for the Blix.
I am using Kodak Ektacolor RA4 Dev and Blix with Fuji Crystal Archive 8x10 in paper.

The enlarger is a Durst 707 colour enlarger.

Any thoughts appreciated.
Thanks

Could be a lot of things, just use the search box on APUG, there are a lot of threads on this topic. Good Luck!