引用自 Nyxx55：

ile muszę czekać żeby error 34 zniknął bo zmieniałem nazwę i mam error

You won't find any official documentation about it.

The unfortunate part about the new profile name change trading cooldown (4 hour cooldown every time you change your profile name) is that page (linked below) will only state, "we have confirmed your account is unable to trade" generic message. Leaving people wondering wtf is going on.

https://psteamhelp.yuanyoumao.com/en/wizard/HelpWhyCantITrade

The error while you trade during this cooldown is error (34).

It took a while earlier last year to figure out Valve silently added the new cooldown.

https://psteamcommunity.yuanyoumao.com/discussions/forum/1/4202490424033360096/