There's been a calibre change (in 2.10) that requires changes to some of the plugins to correctly support keyboard shortcuts. Specifically, plugins that change their menus dynamically. There's been discussion of this already
here.
Several of the plugins affected are by kiwidude. I've been in touch with kiwidude, he doesn't have time right now to work on correcting these issues. But he has given the go-ahead for us (the PI dev community) to update them.
I've posted test versions of my own
FFDL and
Reading List that I've updated. I've done some testing with them on calibre 2.10, 2.9 and 1.48 and they seem good. I'd like to hear if anybody has problems with them. Confirmation that they fix the shortcut issue for you would also be appreciated.
I haven't made a comprehensive list, but I expect Open With and View Manager at least will also require changes.
Please post if you have suggestions of other plugins that will need updates for this issue.
If any other PI devs would care to help with updating kiwidude's plugins, see the rebuild_menus() function in Reading List's action.py or the earlier
discussion thread. And please post which one(s) you're working on so we don't duplicate effort. Thanks!