I have Mac mini 2014 2.6ghz 8gb ram 1tb hard drive. I had 4 partitons 250gb each. It was super slow. I just ebayed a super fast Lacie rugged thunderbolt and installed Catalina on it. I then erased the internal hard and figured out how to make it 1 big partition again. But it only shows 750 gb. I tried in recovery mode also. No dice. It clearly says 1tb in the text on the right of the blue circle. But the blue circle says only 750gb. Never had a problem like this before. I have downloaded several other free partition programs and trials and nothing seems to help.