When it DOES have 2 instances in task manager, it often shows path to the open file, for one of the instances, under task manager "Command Line" column.
When this happens, there doesn't appear to be 2 reader UI's open on desktop. But, if I close one of the files (from Foxit UI) the separate process for the file (shown in Task Manager) keeps running long after the file is closed. There's also the process listed separately for the reader application itself, AND the other instance, showing actual path to file, under task mgr's Command Line column when this happens.
Not sure if it's a bug or special circumstance causing a 2nd, separate Foxit instance to show in task mgr. If Foxit opens a separate process in Windows when a pdf is opened (that process uses a good bit of resources), then it should close the process fairly quickly, after the open file is closed in Foxit.
The only ways I'm opening pdf's is in Foxit are - File > Open;
from Explorer - R click a pdf >Open (Foxit is default reader);
or R click file in Explorer & use Open With (again, Foxit is there, listed as default app);
From an email attachment - R click>Open (Foxit is default reader set in Thunderbird). I'm NOT using Foxit plugin for Thunderbird.
I'm fairly sure it shouldn't open 2nd Foxit instance, unless I launched it a 2nd time. Not sure it'd even allow that. Any suggestions?