It looks like a bug, to me. Adding some debug message calls, I see that the first n (after p p), correctly calls my-forward-word, but the second n then is interpreted in my-backward-word-map, not in my-forward-word-map.

IOW, the call in my-forward-word of (set-transient-map my-forward-word-map t) seems to have no effect.

(And you get the same behavior if you bind M-n instead of n and M-p instead of p, in the transient maps; IOW, if you try to use only M-n and M-p.)

Unless someone points out something we're missing, you might consider filing a bug report: M-x report-emacs-bug.

It looks like a bug, to me. Adding some debug message calls, I see that the first n (after p p), correctly calls my-forward-word, but the second n then is interpreted in my-backward-word-map, not in my-forward-word-map.

IOW, the call in my-forward-word of (set-transient-map my-forward-word-map t) seems to have no effect.

(And you get the same behavior if you bind M-n instead of n and M-p instead of p, in the transient maps; IOW, if you try to use only M-n and M-p.)

Unless someone points out something we're missing, you might consider filing a bug report: M-x report-emacs-bug.

Yes, I'd say that it is definitely a bug. I just tried it in Emacs 24.3, for which the function was named set-temporary-overlay-map instead of set-transient-map, and there it works. So this is apparently a regression, introduced in Emacs 24.4.

Please file a bug report.

It looks like a bug, to me. Adding some debug message calls, I see that the first n (after p p), correctly calls my-forward-word, but the second n then is interpreted in my-backward-word-map, not in my-forward-word-map.

IOW, the call in my-forward-word of (set-transient-map my-forward-word-map t) seems to have no effect.

It looks like a bug, to me. Adding some debug message calls, I see that the first n (after p p), correctly calls my-forward-word, but the second n then is interpreted in my-backward-word-map, not in my-forward-word-map.

IOW, the call in my-forward-word of (set-transient-map my-forward-word-map t) seems to have no effect.

(And you get the same behavior if you bind M-n instead of n and M-p instead of p, in the transient maps; IOW, if you try to use only M-n and M-p.)

Unless someone points out something we're missing, you might consider filing a bug report: M-x report-emacs-bug.