Hi Oleg Ilin,
I have tested this use case in the most major browsers and it appears this behavior to occur only on our website.
If you test it https://www.htmlelements.com/demos/grid/row-resize/index.htm that the issue will not be present.
We will fix it as soon as possible.
I also would like to thank you for your cooperation and reporting this issue!
Please, do not hesitate to contact us if you have any additional questions.
Best regards,
Yavor Dashev
Smart UI Team