There are two questions (with answers) on the Esperanto stackexchange dealing with this problem (and yes, it is perceived as a problem even among Esperanto speakers):

The conclusion is: The double letter should be pronounced differently from the single letter, and it should be a true double consonant (not just a long consonant). Finnlando becomes hard to pronounce by these rules, and Esperantists are in fact shifting to the word Suomio.