I have created a Glossary (with entries with attachment) on my local moodle test site, on the Front page. Using the method described in my previous post, I have successfully done a backup and restore of that glossary (including attachments) to another moodle site, my online test site.
Please note that for the Glossary restore operation to be successful you must of course have ticked the Include a topic section box in your new site's Administration ► Front Page ► Front Page settings.
Could you please say exactly what error you got and at what stage (a screen dump might help)?
You write:
I've also tried to 'Import' the Glossaries into another course on Site A, but the Import feature doesn't seem to find them.
This is too vague.
The only I can help is for you to copy exactly the error messages or provide screen dumps showing what happens.
ATB
Joseph