Debugging with BlobRunner and IDA Pro

I'm following a CTF writeup where a shellcode is debugged with IDA Pro using BlobRunner. I can't reproduce the tutorial: BlobRunner generates a different base address every time (I don't know if this is normal) and it's obvious that they are wrong addresses. I need someone who is able to successfully follow the tutorial and explain to me what I'm doing wrong. I'll share files through chat.