Failures after battery replacement

I purchased a new battery from IFIXIT and also got the tool kit to use. I printed out the replacement procedure and followed it precisely, taking care along the way. It seemed straightforward and everything seemed to go as planned. Upon startup after replacement I now have these symptoms. It boots up very slowly now and pauses during the process, but finally does complete the process , Also the cursor is positioned at the top right of the screen and the track pad is not responding . The pop up box is showing up asking for user name input/etc but when I type on the keyboard , nothing happens. I can force shut down restart with the power button though. I was able to fully charge the battery (plus the additional charging that was recommended). Currently working on draining the battery as also recommended.

Also the fans are running at high speed during this whole time. Much louder than normal but not noisy just fast speed.

I took the bottom cover back off and inspected the cable connections on the logic board/etc. Nothing obvious found yet. The plug/jack connections look good, I didn't find anything obviously disconnected. I am thinking I might have to re-disassemble the unit to inspect more closely. Any tips on what I might have done wrong or damaged inadvertently ?

Thanks,

Dan