CPET with right catheter bizarre results

Hello,
New to the forum. Here is a quick overview of where we are:

42 year old F, Positive PCR, March 2020 (long covid).
1 day at (level 3 trauma) hospital, transferred to (level 1 trauma) hospital ICU (not on ventilator) Treated with Chloroquine, heavy antibiotics, antivirals etc.
very long recovery via extensive PT.

The issue we are faced with now is that although recovery was progressing, elevated HR would cause dizziness, and standing from a sitting position would cause severe dizziness (likely PoTS). Also very low blood pressure (hypotension), and gastroparesis.

To try to further understand what might be going on we went for a CPET with right heart catheter. We were under the assumption that this was likely a cardiac issue but the results have stumped the doctors.
They found no signs of pulmonary hypertension nor any heart failure but her heart is not pumping blood correctly. The doctor indicated that the output level at rest should be around 5 and increase dramatically upon exercise.

The test showed a starting level of 0 and under exertion instead of a positive number it dropped to a negative 4. Which essentially means blood was being pulled back into the heart instead of out.

Additionally due to some apparent mitochondria damage, oxygen is not being transferred correctly into cells.

If anyone could offer some guidance or has ever heard of such a thing it would be greatly appreciated.