Ok, I got this fixed in 2 seconds. I added the following code to your Custom CSS –
.flexible-widgets .widget {
clear: both;
/*overflow: hidden;*/
}
Either the clear: both
or the overflow: hidden
would fix it, but I just used clear: both
for now and left the overflow
commented out just in case you need to use that in the future.
If you want to see it or adjust the code you find it in Appearance > Customize > Additional CSS.