@Fred-Gilbert said in Sluggish:
Could haze from Canada fires slowing GPS?
It can potentially affect accuracy a little, but not the speed the signal is received:
https://whichsatnav.com/does-smoke-affect-gps-signal
As Jack says, minimising the delay is 'work in progress'. My experience is that the delay is just rendering the current position arrow, but everything else (distance to next junction, etc) is accurate.
I have grown used to it over the past 3,000 miles. Very occasionally I get caught out on the odd junction if I don't examine it carefully, but it's much rarer than I feared from my early observations/practice runs.