Chase Stokes Sparks Kelsea Ballerini Split Speculation

It seems like Kelsea Ballerini and Chase Stokes are done for good ... following speculation they reconciled after their split in September.

Chase had fans doing a double-take Thursday when he posted cryptic messages that appeared to be about a relationship gone wrong ... taking to his Instagram Story to say he's "blocked" and "did nothing wrong." He also apologized, adding ... "I tried."

He added more fuel to the speculation with a second post, writing ... "I'm sorry for those who believed in us. It is what it is. Onwards and upwards."

We've reached out to reps for both stars ... so far, no word back.

The country crooner and the "Outer Banks" star were together for nearly 3 years before we confirmed in September they went their separate ways. However, there were reports of them being spotted holding hands in Croatia -- where Chase was recently filming the hit Netflix series.