paypal callback error with sandbox tests

I created and assigned callback page.
Added seller email from sandbox in payment DT config.
Tried to pay one listing, entered buyer account in sandbox, sent payment normally.

But. Paypal stops in the ‘your payment worked’ page. There is no automatic redirection to the callback page in sandox only or no auto redirect at all ?

I tried click the ‘return to sender’ button, it gone correctly to my /callback page, but then it errors : ‘payment failed – no money has been credited’. What happened ? :/

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