Timer class now working properly in Wemos_mini_D1

[il-gen]

When I set timer using --Timer timer(t_s)=std::round(1e6 / f_s);-- it seen not working properly..
I added a time control line:
now = micros();
diff= now-last;
if (timer){ // returns true once every (1/f_s) sec, determines sampling frequency
last = now;
Serial.println(diff));
but result show me Timer class time constant smaller than expected..
(Actually <AH/Timing/MillisMicrosTimer.hpp> librarry is well structured but i cannot understand what is going wrong?)