The md5sum of the Twrp I’ve flash in october is
twrp-3.2.3-1-a5y17lte.img.md5 file content :
It’s downloadable with the image, you can check it with command :
$md5sum -c twrp-3.2.3-1-a5y17lte.img.md5
or to calculate it :
If different try to download it another time (download corrupt)?
Why not try with the tar file (then untar it, and flash) or try with an older version ?
If not try with adb like @harvey186 suggest.
No more idea…