All elements collapse to a single row when using cellHeight() #1579

Subject of the issue

Updating element heights with cellHeight() causes all elements in grid to overlay over each other on first row.

Your environment

• Gridstack v3.1.4 (HTML5)
• Firefox 84.0.2 AND Chrome 89.0.4384 dev (arm64)

Steps to reproduce

Reproducible by updating cell height with cellHeight() on any of the provided demos.

Expected behavior

Cell Heights on grid should adjust based on parameters in cellHeight()

Actual behavior

Elements from multiple rows collapse into the top row and are all overlayed/stacked on top of each other.