https://www.breitbart.com/border/2018/12/28/graphic-cancun-wraps-2018-with-at-least-540-homicides/Attached is an article showing Cancun finishing 2018 with 540 homicides.
Local Homicide Cases Per Year
2018 — 540 (as of December 28)
2017 — 227
2016 — 61
2015 — 37
2014 — 21
That is way more than double last year and 25 times increase in 5 years.
The trend is worth taking note and indicates the general area is far more unsafe than in recent years. I agree it is probably ok to get to your resort and park it. Not sure id wander around and/or get in a cheap local bus ride down the coast to Tulum.