When adding an image in a matrix block - preparse only works on second save

[terryupton]

So I am using a Matrix block and Imager with Preparse. I have a prepares field part of the image block within the Matrix field and the following code;

{% set image = matrixblock.image[0] ?? null %}
{% set alt = (matrixblock.caption ?: image.title) %}

{% set imageRatioWidth = 16 %}
{% set imageRatioHeight = 11 %}
{% set mode = 'crop' %}
{% set imageSizes = [
	{ width: 1600 },
	{ width: 1400 },
	{ width: 1200 },
	{ width: 800 },
	{ width: 600 },
	{ width: 450},
	{ width: 300}
] %}

{# Set Srcset Transform #}
	{% set transformedImages = craft.imager.transformImage(image, imageSizes, { mode: mode, ratio: imageRatioWidth/imageRatioHeight, position: ('50' ?? image.focusPctX) ~ '% ' ~ ('50' ?? image.focusPctY) ~ '%', jpegQuality: 80 }) %}

	{% set largestImage = transformedImages[0] %}

However, the preparse field only seems to run/work when the article is saved on the second instance. If I add a new image block, upload the image to the assets manager and choose the uploading image. Then save the post nothing happens. if I save the post a second time, the preparse works.

Is this a bug or is my setup slightly wrong?