slowing down short bird sounds

I'm looking for an effective way to slow down bird vocalizations without changing the pitch, and someone suggested I try Reaper. I've tried a number of things with Audacity and Raven Pro but haven't had much success. For example, I've used Audacity's Tempo function on a "buzz" call from a Canyon Wren - the buzz structure is actually around 15 up/down pitch changes in a very short (.2s) time frame. Tempo lengthens it and maintains the pitch, but the number of pitch changes doubles (!). Anyone have advice on how to do this? Maybe an AI tool can generate the missing areas after the tempo is stretched to avoid a pitch change? The files are sampled at 48khz so i don't have the luxury of a higher sample rate. Here are samples from the audacity actions - one is original, one is tempo shift keeping pitch, and one is tempo shift with pitch change. https://drive.google.com/drive/folders/1Z57hqXTMLTEX0iYzbyVBqWf-P2ZZF1PM?usp=sharing

Thanks!