Happy Mothers Day Gramma
In case your brood is visiting and you need that fixed ASAP I'm going to take a stab that the blue portion needs to rotate left or right to control the mixing valve underneath. It may have been reinstalled a few degrees right or left of center changing your flow mixture to the cold side. You mentioned you have shutoff`s under the sink so also be sure the hot is not seized part way closed before you attempt the adjustment.:thumbsup:
In case your brood is visiting and you need that fixed ASAP I'm going to take a stab that the blue portion needs to rotate left or right to control the mixing valve underneath. It may have been reinstalled a few degrees right or left of center changing your flow mixture to the cold side. You mentioned you have shutoff`s under the sink so also be sure the hot is not seized part way closed before you attempt the adjustment.:thumbsup: