Stringing has five plausible causes, but rarely all at once
Fine strands of plastic left between separate features are one of the most commonly asked about FDM defects, and also one of the most over-solved: makers frequently change temperature, retraction, and travel settings all together, then cannot tell which change actually helped. This tool separates the plausible causes, moisture, temperature, retraction, travel-path length, and ooze-control settings, and ranks them from what you describe, so you test one category at a time.
How the triage works
Filament left open to air raises the moisture hypothesis significantly, since moisture turning to steam at the nozzle tip is a very common stringing cause that a settings change alone will not fix. A recent temperature change points directly at temperature. Mostly long travels between features raises travel and ooze-control settings, since those specifically target oozing during extended non-printing moves; mostly short travels shifts weight toward retraction instead.
Worked example
Stringing always present, filament left open to air, mostly long travels between features, no recent temperature change: the tool ranks moisture as the top hypothesis given the open filament exposure, with travel/ooze-control settings as the alternative, since the long travel distances described are also a real contributing factor worth testing if drying does not fully resolve it.
A common mistake
A frequent error is chasing retraction settings for weeks when the actual cause is moisture, since retraction changes have an immediate, visible effect that feels productive even when it is only partially addressing the real problem. If retraction tuning has not fully resolved stringing after a reasonable attempt, step back and test moisture before continuing to fine- tune the same setting further.
Limitations
This tool ranks plausible causes from the symptoms you described. It cannot see your printer, so treat the ranked list as a place to start testing, not a confirmed root cause.