Random heat damage in deep space

My craft appears to be taking heat damage and multiple solar panels have burnt off while I’m in deep space and have no apparent heat source nearby. The craft’s heat is oscillating up and down on every part other than the command pod, which is steady at 15.6°C while the other parts are around 230-300°C. This unfortunately burns up my solar panels. This only started after I started a planned burn with the current stage, which should be in-progress in the sandbox, but the heat will continue to oscillate after stopping the burn. This is quite an odd and frustrating bug I’ve encountered before and makes deep-space flight difficult and frustrating.