From what I understand, the problem has been with people from Venezuela fleeing their troubled country and coming here to work, but without legal status in Panama. There has also been this loophole in the rules. You are allowed to stay in Panama for 180 days as a tourist, but if you leave the country for some unwritten amount of time, usually three days, you can reenter Panama and get another 180 days. Some people from Venezuela tried to do this recently and were not permitted to come back into Panama. So far, as far as I know, no one else has been denied entry back into Panama. But there seems to be a trend towards tightening up border security and enforcing immigration laws, so it is quite possible that anyone who lives here as a tourist doing “border runs” won’t be able to continue this.
I checked Chiriqui Chatter since Mr. Williams in our embassy warden. Click the link to read his post, and I am also sharing here the response from the US Embassy.
We here at the Embassy have reached out to immigration to obtain details about the news pasted below regarding the implementation of immigration regulations. According to the Duty Chief at Migracion-Paso Canoas, the PNM Immigration Director is enforcing these migratory requirements across Panama. This means that if an Immigration Official determines that a foreigner is using tourism status to reside in Panama, the entry will not be allowed. The Duty Chief gave examples of this situation, indicating that persons who exit Panama before the 6th month approaches and re-enter after three days, which is a clear sign that the individual is residing in Panama under a tourist status, will not be allowed re-entry.
In summary, these regulations were already in the books but now it seems the immigration authorities throughout Panama are going to be stricter about enforcement. That said, we have yet to receive a complaint from a U.S. citizen actually denied entry at the border for the reason outlined above.
Someone posted the latest information that the Canadian Embassy received from Panama immigration and it is essentially the same.
Tourists may only remain in Panama for a maximum of 180 days. If you wish to remain in the country after that time, you must change your residency status. If you attempt to renew your stay in Panama by travelling out of the country for a short period of time with the intention of returning to Panama as a tourist, immigration authorities may deny you re-entry, as they are implementing stricter border controls. Consult Immigration Panama for more information.
It seems to me that anyone living here as a tourist would be advised to either get legal or consider moving elsewhere. There is no guarantee that the border hopping and perpetual tourist thing is going to work for much longer.