Mid-2015 Macbook Pro won't recognize my Thunderbolt Display
Hello,
I recently purchased a used Thunderbolt display to use both with the 2019 Macbook Pro that I use for work and my personal mid-2015 Macbook Pro. It works great with the 2019, using the adapter for the USB-C port, but my mid-2015 won't recognize it in either port. I tested the monitor with both laptops before purchasing, and it took a few minutes for the display and 2015 to work together, but they did. However, I have not been able to get the 2015 to recognize the monitor ever since. I have not ever used the thunderbolt ports prior to this...is this likely a problem with the ports?
MacBook Pro 15″, macOS 11.5