This may or may not help...
Check the "Count-in/Met" settings in Preferences and make sure that they're all set the same as those settings I've with red rectangles on the image below.
You'll need to regenerate your song after adjusting these.
Also, is the volume of the Drum track set to 90 and not zero?
Lastly, in Reaper, it's only necessary to set up one bar of rhythm to use as a click track. Once that's done, make sure it fits exactly into 1 bar (use snap to gridlines).
Now, right-click on the single bar and choose "Glue Items".
With your mouse cursor positioned over the right edge of that bar, click and hold down the mouse button and drag the bar to the right. It will be copied as a loop to the other bars.
Regards,
Noel