Don't take it the wrong way , but you are IMHO making attempts to help you more difficult than needed.
Post a DETAILED, EXHAUSTIVE description of your setup (the EXACT specific "Linux" PXE Server and how it is configured - or at least what pacjets it sends) AND a complete, full description of ALL the settings you have in TFTP32 (provided that it is working in your setup ) AND a complete full fescription of ALL the setting you have currently in TinyPXE.
Describe also your hardware, it is not common to have a PC with two network cards that gets both net addresses by DHCP (at least this is the first time I hear of such a setup : ) AND describe your goal, i.e. WHAT EXACTLY are you try to PXE boot and how this is setup/configured.
It seems to me like you have a complex setup, it needs a complete description.
Otherwise, you will likely have another suggestion, and that will be non-working because of some other detail that you either did not provide or have mis-configured, and then you will loop through yet another one, that again will result in a failure, so you will add some other snippet of info and loop again ...
There are REASONS why the "Standard Litany" is "standard" :