Anyone with experience from Baseus PowerBanks?

I thought I had my vacation plans laid out.. Or well.. My patience during my vacation! I bought a Baseus Adaman Powerbank 65W with 20 000 mAh..

After a long hefty charge, it reached something at about 80.. Then it reset to 0.. And I don't really see why. Has anyone else experienced this? Is my unit defective or is it as if its charging two batteries within it or something?