Issue with "SEO Google Image Sitemap"

I am using SEO Google Image Sitemap and I thought it was working fine in my OC 1.5.6 shop but Google search console says it is not working.
I asked a question at the extension-page but it looks like the developer does not respond any more.
Another user posted a link to his sitemap but when I had a look at that link I saw the same error as in my sitemap.

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"IP_CAM 3 weeks ago
Seems to work perfect in my latest Test OC v.1.5.6.5_rc based Test Shop:
http://www.evelo.li/shop/index.php?route=feed/imagemap
Thank you very much!
Ernie

Dunald
Dunald 3 days ago
There is a bug, if you have a look in the sitemap you see
http://www.evelo.li/shop/index.php?rout ... mp;path=18
If you visit that link there is "category not found" but if you remove the "amp;" you see the notebook catagory.
Same problem in my site and Google search console says this is a problem
Does anyone have any idea how to remove the "amp;" from the url?
Image url is ok but google does not know what product to link to what image because the amp; breaks the url to the product."
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Any idea of how to make this extension work without the "amp;" ?

Well, there is a Bug, as it looks, but I seem to have found a dirty quickfix for it!
It's sure not a Pro-Solution, but I am not Coder enough, to make it better..., it was the
only & I found, related with this Mod!
Good Luck !
Ernie
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http://www.evelo.li/shop/index.php?route=feed/imagemap