Yes, 'Hold minimum power' should help, because your water temp is 27,74 and your "Startup temperature' is 28, yielding zero on the Controller Curve.
You have an extremely narrow allowable power range for the fans (45% to 60%), so your controller has 45% power as the minimum (which will be 'hold'), to 60% at full speed.
I have my fans at 20% minimum with hold (never stop), and 100% max... not that that design is definitive, but it works the way I want.