For internal reasons, we changed our URL dynamic syntaxes about a month ago to better identify product, category and manufacturer pages. We created 301 redirects for all products to take care of traffic from the old URLs and resubmitted our sitemaps. Around the same time, we also launched a parallel TLD site for Canada and implemented the geo-targeting (and geolocation redirects) for both sites.
Currently, Search Console is only showing 2100 pages and 850 images as being indexed. However, when we do a "site:example.com" search, we get about 24000 results, roughly what was indexed (and visible in Search Console) before we made the formatting change. By comparison, through the same period, we saw no dramatic change in the index levels in Bing Webmaster Tools. Bing is indexing 95000 pages, roughly a 4% increase from the time of the change.
I'm looking for some feedback on whether we have a problem and I welcome any suggestions on steps we should take at this point to improve the indexing.
Also, I'd like to understand why (and how) bing will index double the pages we've actually submitted in our sitemap and four times what Google is indexing.