Does the Infinix X6515 Smart 7 have any Wi-Fi restrictions in certain countries or environments?

Yes, the WLAN function is restricted to indoor use due to its operation in the 5.15 to 5.35 GHz frequency range. Additionally, the device is subject to restrictions when placed on the market in numerous European countries including Belgium, Germany, France, Italy, Spain, and others, as noted under Directive 2014/53/EU. (Page 7)