Unnecessary window refresh

Hello,

we have a TEXT-global which contains html data. This html code contains -Elements. So far so good.
As soon as I change another global of type DATE (and only in this special case), the whole html code is rendered again and for a short time all the images are reloaded. This I can see because the images first will be replaced by the default placeholder and then will be replaced by the correct images.
Two questions: Is there a solution, that the html code will not be reloaded when another global of type DATE has been changed? (By the way: There is no method which is triggered when the DATE-global has been changed).
Is it possible to suppress the default placeholder in every case (or to change the placeholder)?

Thank you!

Christoph