Subject of the issue

grid items slowly vanish (overlap?) if columns are adjusted too quickly then compact is requested. the grid items end up with negative gs-y coordinates. likely due to the column resize animation still being in progress when the math for the compact starts?

Your environment

gridstack-jq.js v4.2.5 on Firefox 89.0; float false; animations enabled.

Steps to reproduce

Fairly simple to reproduce in any project: https://jsfiddle.net/3ryc08as/

Stress test case:

            for (let j = 0; j < 5; j++) {
                for (let i = 1; i <= 12; i++) {
                    console.log("gridding at", i);
                    this.grid.column(i, "moveScale");
                    this.grid.compact();
                }
            } 

Bonus bug: there's an infinite loop if .column(0) is requested.

Expected behavior

no race conditions between automatic column re-calibration and compaction.

Actual behavior

random subsets of .grid-stack-item elements end up with negative gs-y coordinates. if many column resizing+compaction ops are performed back to back (animation delay problems?), all smaller items eventually get hidden behind the largest item.