The U.K. chose to use the eu open tender process, if they had wished to not do this they could have.
This was a choice the government made and was not obligated to do so under eu rules.
The French for example chose not to follow this process, but instead awarded the contract to a French company as allowed under eu rules.
“French passports are made by Imprimerie Nationale, the state-run French printing organisation, with the French government having made the decision not to put the job out to tender, as allowed under EU rules”
https://amp.theguardian.com/politics/2018/mar/22/contract-to-print-uk-passports-abroad-will-save-120m
Stop spreading misinformation about why British passports are produced in Poland.
It was the uks independent decision that led to this situation, not eu rules.