I have reproduced this issue a number of times.
Device F6X Pro
Phone: OnePlus 6T
Background
Having not used PacePro before but had been meaning to incorporate it into my training and had upgraded watch for this and music plus interval prompts w/o carryingh phone I was kind of irked to get "oops [...] try again" every time I tried to send a strategy from the PacePro screen. Super miffed to have had to boot up garmin express and drop it onto the watch that way and delay starting that days training.
Investigated today as to why. Turned of all devices logged into my connect app and all watches. So that only Fenix and main phone were on. Still no good. However, I found out the plans will send from inside the plan details screen.
Steps to reproduce:
1)Navigate to PacePro
2)Click "Send to device" icon next to a plan.
3) Rec'v error message
4)Select plan
5)From within the detailed view of the plan click the send to device at the top right of screen
6)Select Watch and plan will send successfully.
I can't be the only one caught out by this.