Aerodynamic properties of vessel changing after save?

[Socraticat]

Ok, first time I thought it was my building skills, but now I'm certain...

I have a vessel that can be classified as a Kerbin capable,  refuelable, VTOL SSTO. I worked very hard to optimize this bad boy: It can reach and land on Minimus, VTOL around Kerbin, Semi-circumnavigate and return... it's legit.

However, it can only do all of these wonderful things after an initial launch. That is: Launch from Dessert, reach Mach 3, refuel at North Pole, reach mach 3, return to Dessert, mach 3, Land on a Mountain, Return to Lowlands, Save.

Upon reload, I can't reach Mach 1! what? I'm so flamed right now. I know it's not a weight issue; it won't reach Mach 1 at half fuel.

I'm certain the craft has the proper aerodynamic properties; I greatly reduced drag after having this problem once before. I streamed an anomaly hunting session on Mixer with iteration 2.

I know you will probably want pics and vids, make a bug report, yada yada... I'll get there if I can figure out why this forum won't accept any of my picture links... but let's start with the dilemma. 

Why is this happening?

Edit: Bug Tracker ID, Bug #22931

Bug Page (pictures included) https://bugs.kerbalspaceprogram.com/issues/22931

Edit2: A livestream recording good until July 2, 2019: https://mixer.com/jEdward333?vod=111380162

Edited June 19, 2019 by Joessep Kerman
Added links and bug ID#

[kerbnub]

I've had similar issues and found out it was the cargo bays. I'm not sure it's fixed in later versions,  but I've found that if a cargo bay was the root part, it would stop shielding the craft after saving and reloading. In other cases I've found non-working cargo bays to be fixed by opening and closing them again.

[Socraticat]

I had wondered about the cargo bay as the root part. This is likely the issue. I'll give it a shot and report after.

I finally purchased KSP on steam. It's probably how I should have started my kerbal journey (although my little yoga might disagree) and I'm hopeful that the more robust PC community will keep me satisfied. 

I struggle with how little support and community there is for ksp on console.  With so many hurdles to breach just to get an update or dlc, I wish I would have known before I purchased on console... hell, it took a year for a working version. [sigh]

Thanks for your input, Kerbnub.

[kerbnub]

Funnily, I'm actually a PC player and didn't see this was a question for console!

No idea if the bugs on both are so different though.

I can hardly imagine playing on console, just for the interface, and that's before even talking about mods. I'm sure you'll like it better