Weird SEO related Problem!

[daneshpayeh]

Hi everyone,
I have recently found a problem in my website that I am not sure if it is related to virtue mart or not!
My Joomla ver is 3.4.4 and virtuemart ver is 3.0.10
I use OSMap (previously Xmap) plugin to make my sitemap XML automatically. It is a nice plugin that automatically makes a XML sitemap for submitting in search engines and ....
I have some products in my store and two categories "Programmable LED Signs" and "Window LED Display". At the moment all products are in both categories.
But my problems:

1- The OSmap plugin lists all of the products in only "Programmable LED Signs" category and "Window LED Display" is empty. But when I open "Window LED Display" category in website, it removes the last product from "Programmable LED Signs" category and add it under "Window LED Display" category!!!
this is my XML sitemap link: https://ledsignsolution.com.au/index.php?option=com_osmap&view=xml&tmpl=component&id=1
and this is my store link: https://ledsignsolution.com.au/store
open the category  "Programmable LED Signs" and "Window LED Display" in store and see how url of product "122*36 CM Full-Color Sign" will be listed in XML sitemap by one of these two links:
   https://ledsignsolution.com.au/store/window-led-display/122-36-cm-full-color-led-sign-detail
   or
   https://ledsignsolution.com.au/store/programmable-led-signs/122-36-cm-full-color-led-sign-detail
depends on the last viewed category!!!
does anyone else have same problem. I am not sure if this is a virtue mart or OSmap bug.

2- my second problem related to how OSmap (previously Xmap) list the products in XML site. it seems that this plugin list them only in one category. but I believe should be list in both. is it only my website or other website have same problem?
and what method do you recommend for making XML sitemap for search engines?

thanks

[PRO]

google only wants 1 link per product in sitemap.

ALSO: google and bing both prefer the canonical version in sitemap

[daneshpayeh]

Thank you PRO,
That is alright that sitemap plugin list product url for only one of categories.
The problem is that It change the url of products in sitemap based on the last viewed category. So each time searcher engines loads the xml sitemap may find same product with different url.
is it ok? or I have to use another plugin or even make the sitemap manually?
What methods for sitemap  do you use for virtue mart?

[jenkinhill]

I use JSitemap PRO for all my sitemaps now, and have not identified any problems with it.

[daneshpayeh]

thank you jenkinhill,
I tried JSitemap and every thing is OK now.