expandable blocks with enum confusion

Im working on some blocks with a +/- to expand the blocks to show more options. At the moment the one block as an enum dropdown in the expanded look.
When the block is first expanded the enum is black and not the same colour as the rest of the block.
Once clicked on it returns to the correct colour. I have tried making the variable a default is the first item on the list but still does it.

Could this purely be a rendering issue or something else going on? Screenshot of the expand block for the first time before any selection is made and code snippet are below.


indent preformatted text by 4 spaces
 * set pixel in OLED
 * @param x is X alis, eg: 0
 * @param y is Y alis, eg: 0
 * @param screen is screen selection
//% blockId="VIEWOLED_set_pixel" block="set pixel at x %x|y %y ||to display %screen"
//% weight=70 blockGap=8
export function pixel(x: number, y: number, screen?: DisplaySelection) {
    if (screen){
        _I2CAddr = screenAddr(screen)
    //    _I2CAddr = 60;