This is a friendly user-to-user forum. Direct your comments about feature requests to Adobe.
You are probably opening a legacy file in a newer version of ID when you do this, so ID always presumes it's a new, unsaved file and automatically goes to the last folder where you did a Save As. Once saved, it will defualt to the same folder as long as you don't change versions. This is a safety precaution as much as anything since ID files are not backward compatible and it keeps you from accidentally overwriting the original.
I tried going to Abode but it always pointed me to here. I called and it said come here. Chat and it said come here. So It did.
Let's assume you're correct.
First, It doesn't give me the "Legacy Formate" prompt. I see this pretty often in AI. As I said above, AI saves to the folder that the file was opened from REGARDLESS. ID just saves with no warning. At the very least I should get the prompt, like I do an AI.
Second. ID is the ONLY one that does this.
Third. If it's a "safety precaution" why does AI, Photoshop etc. NOT do the same thing. At least make it consistent.
Finally. I'd love the option to turn this off.
Here's what makes me doubt your answer. Some of the files I've had this problem with I KNOW, for a fact, are NOT older versions of ID.
Do you see the word “converted” in the title bar? If so, it’s being read as an earlier version.
InDesign cannot save its native format for earlier versions and so you won’t get that option. Photoshop files are backward compatible.
Whether you accept it or not, InDesign has behaved this way since InDesign 1.5 was release about 15 years ago. This is nothing new.
You are receiving advice here from some of the most knowledgable InDesign experts around. I suggest you listen carefully to their comments and try out their suggestions.