XCTest table snapshot failure with Xcode 11.4

With the latest XCode 11.4.1, we have an issue running the UI Tests. The method that is failing is connected to reading the cells from a table view:

    func count() -> Int {
        let table = app.tables.firstMatch

        return table.children(matching: .cell).count
    }

The error that is shown after a couple of seconds is:

Failed to get matching snapshots: Timed out while evaluating UI query.

The same error is received if I won't enumerate the table view cells in order to click every one of them:

table.cells.allElementsBoundByIndex

I saw the release notes for XCode 11.4 and tried to set up executionTimeAllowance but didn't change anything.