Matchmaking client error - Item hover infobox does not appear

Items in item set creator only show their infobox when mouse-overed a few times, until they just don't react any more. Happened every time I tried. Error persists until matchmaking client is restarted. Then every item allows for a few mouse-overs again, until it goes unreactive again.

Error reproduction - happened in 100% of all cases I tried: Mouse over several items repeatedly, going from one item to another every time. After 2-4 hovers, there is no more response from these items. Error does not occur when only one item is mouse-overed repeatedly.

I cannot add a useful screenshot as my cursor is not shown on it.