Hello Steve,

In general, if any viable workarounds emerge, we will share them as comments here in the public discussions. Currently, we are not aware of any viable workarounds for this specific bug. Regarding your question on how to track when the filter menu is open, you can hook into the click event of the body and track which element the user clicks on. If the element happens to be a column menu option and the text of the element is "Filter," then it indicates that the clicked element is the one responsible for opening the filter menu.

<script suppress-error="BL9992">
    const body = document.getElementsByTagName("body")[0]

    body.addEventListener("click", (event) => {
        if(event.target.textContent.includes("Filter") && event.target.classList.contains('k-columnmenu-item')) {
            console.log("filter is opened")
        }
    })
</script>

Here is a REPL example that demonstrates this approach: https://blazorrepl.telerik.com/cnkLaTYs38kErCBT10

I hope this helps.

Regards,
Yanislav
Progress Telerik