When url SEO is active ps_wirepayment redirects to admin login after purchase

[franquero]

Hello,

I'm developing a shop with Prestashop 1.7.6.3

I've activated credit card and wire payment, both tested and working.

Later I activated SEO standard option to modify URLs, and it works changing default urls to human and search engines more friendly ones.

The problem is that when I try to finish a order with wire payment, the shop doesn't redirects me to the order confirmation but to the admin login page.

I tried with credit card payment and the shop redirects me successfully to my bank payment platform, although I haven't finish the order to see if the shop redirects me to the confirmation order page.

It is obviously a redirection issue in the order confirmation step. How could I fix it? My language shop is Spanish, and the SEO friendly url for order-confirmation is confirmacion-pedido.
All others friendly urls are working fine.

I'm working with Debian 9 and nginx.

I will appreciate any hint you can help me with to fix this. Thank  you in advance for your help.