High ping times in speedtest via transparent proxy

Im having problem, when my clients (or me myself) check speedtest via transparent (nat/redirect rule) the latency goes higher about 250ms…

When i go through direct masquerading the latency stays about 10-25ms average…

Please verify this issue..

Also the page loading takes 1+ second before it starts downloading page from webservers…

Mikrotik X86 v3.30