Altimeter Inaccuracy

Not sure if this the right place to put it, but I found the altimeter to be a bit inaccurate. When comparing altimeter data with the F6S & Strava's corrected number(these two numbers were only 15 feet apart) the FR945 LTE was off by 329 feet(which I think is a bit much). Both the FR & F6S started at pretty much the same elevation(2ft apart) & ended at the same elevation(2ft apart again). / is it possible to have people at Garmin check this out & see if there needs to be a correction done in firmware? Thank you.