I just came back from Akumal the first part of December and did not encounter this, but word has it that the beach access road into Akumal has been blocked due to a protest which is currently going on. The protest is being staged by locals who are against the new proposal to charge a fee (USD $12 p/p) to enter the beach area. This is interfering both with tourists who are staying elsewhere and want to snorkel at Akumal Bay and with those who are staying in the area in a condo or other rental. Check back for updates! In the meantime, here is a link to an article which explains a bit more about the situation.