My dryer vent was setup to go thru the wall, up 2 stories, to my roof
As a general rule, dryer vents should be cleaned out with a brush (attached to a long chain or rope or flexible rod so they can be run through the duct) every 6 months or so. If the arrangement of the vents in your townhouse community is such that you cannot easily do this yourself, you should take it up with whatever owners association or management company there is overseeing the site, since lint clogged dryer vents can be a source of fires, which should be a concern far beyond the impact on your dryer's performance.

If you applied something like a leaf blower to the bottom of the duct, you may have blown the cap on the top right off it, which would add to your problems.