Missing ALT tag / Add missing ALT attributes not working

I’ve searched/read the other support tickets, but was unable to find the solution. All my images in the media library have alt tags inputted and, as far as I know I’ve entered alt tags wherever applicable within the website. Moreover, I’ve checked the feature “Add missing ALT attributes” within the plugin, but still does not resolve the issue. Here is the results from the RankMath SEO Analysis:

Also, even though I am aware that the SEO Analysis is only an internal feature how do I exclude certain results that I am unable to modify (i.e. html size). I am using this report to show my client the progress of his website and I’d rather not have to take the time to explain something to him that is totally irrelevant.

Many thanks!