MBP extremely slow after SSD Upgrade. What's wrong with my mac?

the hard drive name has nothing to do with it. You can name it whatever you want as long as you select it in the system preferences control panel as the startup disk.

How do you set it to the new SSD? It still only has the Mac HD listed.

Here is what worked for me. I did a SuperDuper clone from a 256GB Samsung EVO 840 SSD to a 1TB Samsung 860EVO. After doing this the MacBook booted up ok but I noticed that there was a click delay on every action and everything seems to have somehow slowed down. Almost like the hardware know that the SSD has been removed and was trying to verify every file that was being opened.

Same issue, different results. Help, never have I seen this in 15 years…