Bug: leftSplit with dragColumns

in Webix 8.2.4 / 8.3.0 is a bug with dragColumn in datatable with leftSplit of some columns. does not work

https://snippet.webix.com/q8cy9tjh

what may be the problem?

first table does not run (similar config to my application)
second table all o.k.

worked fine with 7.xx

ok… found out: error occurs when leftSplit = “3” instead of leftSplit = 3