I don't have air recirculatory setup but I have a question for you...

do you mean the fresh air (as it now) is coming from under the dash and NOT
thru the vent openings on the dash?

if so then the flexible air ducts under the dash are broken or disconnected
and they are not bringing the fresh air to the vents opening anymore. To
fix this you have to pull the dash or try to fix them by crawling under the
dash.

good luck