Thanks for the report. Looking at the two sample URLs you shared, the only differences seem to be the order of the parameters, which shouldn't have any impact, and the presence of the 'from_login' parameter, which also shouldn't affect the functionality itself. It sounds like this is likely related to the browser itself, as you mentioned it only happens with Edge.
To help track this issue down, can you let me know if this also happen for you with that browser with the demo on https://www.dropbox.com/developers/chooser? (I just tried it myself with the closest version of Edge I have available, 44.17763.1.0, and it worked fine for me there.)
Thanks for the response. It worked fine for a couple of months but since last week we are facing the same problem again in Microsoft Edge. We tested the site you have provided and that is working fine for us.
Since the instance on the Dropbox site works for you, it sounds like there may be something in particular about it on your site that is causing an issue in Edge. Could you share a link to where on your site we could reproduce the issue so we can investigate? Feel free to open a ticket here if you'd prefer to share privately. Thanks!