Menopace Plus is just a vitamin and mineral supplement with isoflavines I believe - so this will not interfere with HRT.
Using HRT in pill form can give an upset stomach or digestive issues but digestive problems often emerge when the meno hits anyway. Vitamin supplements can also upset the stomach. There is some research that shows that ‘some' women find that flushes reduce when taking isoflavines(phytoestrogens) and I understand there are some benefits for the bones and heart but whether phytoestrogens interfere with HRT I'm not sure.
If you know you diet isn't good or you are having food absorption problems that some vitamin and mineral supplements can be a good idea but can never replace a good diet. It is however sensible to take vitamin D3 in winter and, unless you eat enough oily fish and nuts, then omega 3 and magnesium supplements could also be helpful. It is very important to have enough calcium in our diet each day as well for our bones.
When you say you started to feel ill and they put you on a different hrt, what symptoms were you getting and what type of HRT are you now using? DG x