PDF , Footer not printed

This issue has been discussed for quite some time in this forum. Letterhead footer not printed on PDF.
Two solutions have been offered,
1- Hostname setting
2-Tick/Untick “Repeat Header and Footer in PDF” in print settings.

Both are not working in many cases. Does anyone know the crux of this issue, and possibly the solution?

This issue is related to wkhtmltopdf version.
If the version is less than 0.12.6 , so many misalignment, mis-formatting are reported. By default, Ubuntu/Debian installations have wkhtmltopdf version 0.12.5

Find the version with command
wkhtmltopdf --version
and if the version is below 0.12.6 , upgrade. We have detailed the steps here