Thanks for your reply. I removed all the P's, partly because it didn't make a difference. I'll add an image of my node settings (Stanza). I think this is in the right place then.
If I briefly power cycle the node after the first startup, during which the Startup_Macro doesn't work, the Startup_Macro works as it should. Only during the first "registration" does it go wrong.
Both my nodes (64565 & 634880) are on the same LAN; the node I'm trying to connect to (629920) is located elsewhere in the country.