To post a track, do the following:
Run the mission and when you have replicated the issue just hit 'Esc' and you will be taken to the debrief screen. On the debrief screen there is a tab that allows you to save the track named 'Save Track'. Click on 'Save Track' and follow the prompts to save the track which will be saved in your Saved Games/DCS...../Tracks folder.
Once the track is saved, navigate to the Main screen and hit the 'Replay' tab. Select your track to view and just confirm that the track has saved and is indeed playing back correctly and illustrating the problem as you experienced it in-mission.
If you are satisfied, exit SIM and post a reply to this thread. When doing so, you will notice a paperclip icon for attachments in the top toolbar. Click on the paperclip and a new window (manage attachments) will pop up. Hit the 'Choose file' tab on the left and navigate to the location of your track file and hit open. Thereafter hit the 'Upload' tab and the track will upload.
Once done, click on the paperclip icon again and the forums will automatically insert the track link for you in your text.
Hit the 'Submit Reply' tab and you're good to go.