*Update* Strangely with the same steps that reliably showed the issue yesterday, it now works as expected so it may not be so easy to figure out.
Here's some exact steps to reproduce the issue with an example wave file.
1) Start a new project with a BPM of 80.
2) In the Media Explorer with Tempo Match on browse to the file below and preview:
https://drive.google.com/open?id=1YD...4AC0giSIln0ezM
3) The playrate should say 1.455.
4) Insert the file into the project by dragging or with an action.
5)
The playrate will now be half what it just was. 0.727.
The expected behavior is the inserted item always matches the preview.
How to fix it:
-Click "Set" beside the playrate display in the item properties.
-Change "Measure Beats" from 8 to 4.
This doesn't always happen, but it happens often and is definitely a new issue as I'd never encountered until recently. Maybe a bug with embedded or implied tempo information?
The other issue mentioned in the original post seems similar as an imported item may have a "Measure Beats" setting of 0.2.2 etc, when the Media Explorer was tempo-matching at 0.2 etc.
**EDIT**
If I drag the file from Windows Explorer Reaper asks if I want to use the tempo suggested by the filename, choosing yes gives the same result as inserting from the Media Explorer. What could be happening is that when the file is inserted from the Media Explorer Reaper acts as if I'd agreed to that (even though the setting is turned off). The media import settings for embedded tempo say the Media Explorer overrides, but perhaps in some instances it doesn't?
The detect tempo from time selection had a similar problem, it always assumed the wrong number of bars. In my experience 4 bar loops are most common, but Reaper assumes 8, which halves the playrate.
Maybe here?
+ Media items: add preference to set imported media items with embedded tempo to auto-stretch at project tempo changes
+ Media items: support calculating playback rate from user-supplied tempo or length in beats