tximport txidcol and geneidcol selecting wrong column
By setting type="salmon" you're overriding your settings for things like txIdCol. The various type options (except none) are presets to set things correctly for the output from various programs like salmon or kallisto. If you need to specify custom column names, set type="none".

As an aside, if I'm interpreting your question correctly you have only two samples in total. You can not perform a meaningful analysis with an unreplicated experiment, so if that is indeed your case then don't waste your time further with this dataset.