I kinda think TOS may have added a timer (in recent years) to insure TOS is rebooted after 7 days of being active! {I seem to recall them recommending TOS be rebooted daily} Your observation of not having the issue and reboot weekly {or sooner} matches that of Jim, who also restarts TOS weekly.
I get these TOS hangs almost weekly (not more frequent), but may be from failing to remember to bounce TOS! -- I leave my systems running 24/7.
Having to manually screw around with (restart) TOS daily would not work for me on my unattended system! If it (TOS) becomes that fragile, I'll have to replace it with a more robust solution -- not a huge issue, but postponing until effort becomes justified. --
I also use the TDA-API primarily for populating my sql db with option data, which has been very reliable for a few years.