Issues with Query mode filters

[dcdamien]

I have a table with 3 columns: key, summary, and reporter_display_name:

There is Query mode filtering set on summary. The datasource is Postgres.
The variable used for filtering is summaryFilter of type Textbox, with no default value:

The query is:

select
  key,
  summary,
  reporter_display_name
from
  jira_dwh.select()
where
  "summary" like '%${summaryFilter}%'

The column is set as below:

In general filtering works - variable value is set and resultset is filtered:

But..

Issue 1.

After entering search term that returns 0 rows, table headers disappear. Please note that the variable is intended to be not visible on the dashboard and I expect that user should be able to clear the filter on column level:

Expected behaviour is all columns specified in the layout should be visibile regardless of query result.

Issue 2.

Clicking the Clear button on the column clears the Search term but underlaying variable value stays untouched resulting in executing query with filter still set:

Expected behaviour is underlaying variable value should be cleared after clicking Clear on filtered column and query should be executed with empty variable.