Pavers do not sink because the material was wrong. They sink because the base under them was never built to hold. What you see on the surface — the dip, the lipped edge, the puddle that never drains — is the last step of a problem that started the week the crew skipped a compaction pass.
That is why the low bid is expensive. It is not cheaper work; it is the same work with the invisible half left out. The savings last until the second wet season.
What makes it worse in Tampa: Clay does not drain. When a base is built without an open-graded layer or an edge drain, summer storm volume has nowhere to go, and the field heaves in the wet season and drops in the dry one.