Odd flanging sound when recording

Hopefully this will be an easy fix. When I have a track armed and I play a VSTi or sample or what have you, I hear this very odd flanging noise, like the track is being doubled. When I play back the recorded audio, it sounds perfectly fine. I checked that direct monitoring is turned off on my audio interface, a Komplete Audio 6. It should be on the latest drivers. My settings are as below: Any thoughts on this? I can't remember it being an issue in the past.

I was gonna say direct monitoring on your interface, but...are you sure it's completely off? You can test by turning off monitoring on the armed track (little speaker icon). You shouldn't hear anything until you play back the recording.

Yup, if I turn off monitoring by disabling the speaker icon I do not hear any audio while recording, only during playback.

Hmm, I guess the next thing to check is that there are no fx in the monitor fx chain or the input fx chain, since both are independent of the normal track fx chain and would only be heard during monitoring.

In addition to foxAsteria's suggestion above (checking the Monitor and Input FX chains), you might also try making a portable Reaper install to a seaparate folder to check if the problem is the same there ...

I wanted to post a followup because this was a real pain in the d-hole but after about an hour tonight of troubleshooting I was able to figure out. I ended up using the portable installation as recommended, and sure enough the issue wasn't there. I tried exporting the settings from the portable install into my main install, and the problem went away. Unfortunately, that also blew away a bunch of my customization. So I opened up the exported settings and started digging around. I found the culprit after exporting my main install settings and comparing the two. Looking under the audio settings of the reaper.ini file, I saw that there were odd values for the direct sound buffer sizes (at least I think that's what they are. In the portable install, they were set to 0 and everything was fine. I used my "real" install backup, edited the file to set all those values to 0, and then imported the settings. Everything is gravy now. So there you have it. Set all of the dsound_devicein_* or dsound_deviceout* to 0:

For the record and for anyone with similar problems in the future, direct monitoring would not affect this if the user is tracking virtual instruments. There is no actual sound to be monitored when tracking through a vsti, the only thing coming out of a midi keyboard is data commands. So if you are experiencing a doubling or flanging sound, enabling or disabling direct monitoring should not make any difference.