I'm a bit confused here. When I run this command twice without moving:
/execute run setblock ^ ^ ^10 minecraft:gold_block
I get back "Could not set the block" after the second time. However, when I do the same thing with this command, I don't get that message on the second run:
/execute at @p run setblock ^ ^ ^10 minecraft:gold_block
Can confirm in 20w49a.