Gnus: Moving multiple articles to a single group

Question

My question is similar to How to move multiple articles from one Gnus group to another?. However the answer given there didn't work for me.

Suppose I want to move multiple articles in a summary region to another group (I am accessing emails over IMAP), I mark all the articles in a region with M P r to get a # mark. Now I do M-& B m to move the process marked articles and specify the target group.

Unfortunately, Gnus is asking me the target group for each and every article which is annoying. What am I doing wrong?

EDIT: Looks like I was unnecessarily pressing M-& (i.e. M-S-&) before B m as specified in the below pasted last paragraph of https://www.gnu.org/software/emacs/manual/html_node/gnus/Process_002fPrefix.html#Process_002fPrefix

Many commands do not use the process/prefix convention. All commands that do explicitly say so in this manual. To apply the process/prefix convention to commands that do not use it, you can use the M-& command. For instance, to mark all the articles in the group as expirable, you could say M P b M-& E.

While commands like expire article (E) will need the above M-& prefix, the commands like B m (gnus-summary-move-article) will honor process marks and will move all marked articles to the target buffer.

Answer 1

What do you mean by M-& B m?

In my Emacs config, M-& (with shift) is bound to async-shell-command, and I think that's a default key binding. If you meant M-7 B m (without shift), then you asked Emacs to run gnus-summary-move-article seven times. It would make sense that it prompts you for a destination seven times.