to ssh into the device you need to know it’s ip address, or corelec.local might also work as an address to connect to. if you didn’t change the hostname when you set the device up.
login: root
password: coreelec
(password might be libreelec if you have upgraded to coreelec from libreelec at some point in the past without doing a fresh install)
then once you have a command prompt, type
cat /storage/.config/autostart.sh
cat /sys/devices/virtual/amhdmitx/amhdmitx0/config
cat /sys/devices/virtual/amhdmitx/amhdmitx0/disp_cap
cat /storage/.kodi/userdata/disp_cap
will show the contents of those 4 files. then just cut and paste the results from the putty window and post here.