Hi, folks.
I'm applying for multiple funded PhDs in Neuroscience in the UK as an international student, and I get multiple rejections.
I'm 26 and I have BSc in Chemistry (Ukraine), MSc in Chemistry (Ukraine), and MSc in Membrane Engineering (International - France/Czech Republic/Portugal/Scotland,UK).
First two are 2:1 (GPA ~85/100), and the last one I consider as an equivalent to 2:2 (GPA 15.8/20).
My last master thesis was closely tied with neuroscience, and I got A-grade for it.
I also have some research experience in neuroscientific research (~1.5 years) and membranes (5 years along with my studies in Ukraine).
I have visited two international conferences, one with an oral report (Istanbul, Turkey), and other with poster one (London).
I don't have any publications yet, but I have multiple abstracts published.

Can anyone give me a clue what am I missing for a successful PhD application?
Where are my weakest points here?
Do I have really low grades for this purpose?
Should I do the third master's in Neuroscience to gain better grades and have higher chances for PhD? (Although, PhD adverts tell me that this field is highly multidisciplinary and they accept applications from a wide range of degrees in Natural Sciences)

Please, help me, I'm so confused...

Hi, PhDs can be very competitive. Your qualifications and experience sound fine, so it could be something amiss with your application, or it could just be a numbers game.

Can you ask a former supervisor to check your applications?

Do you tailor your applications to the post every time?

It doesn't matter about your publications at this stage. Don't do a third masters.

Keep applying.

Without seeing your application it is impossible to advise you on what you are specifically doing wrong (if anything). Having a 2:1 or a 2:2 is not a great start though if you are applying for highly competitive positions although it is difficult to know how to equate your grades with UK equivalents. I may well be criticised for this but in my personal opinion nobody should be undertaking a PhD without having excelled at undergraduate level first and by that I mean achieved a solid 1st class degree. I just don't think it is fair on the students who are underprepared for the PhD as a result of not having a solid foundation in their subject. This is my personal opinion only and I know many disagree with me. Plenty of people do go on to do PhD's with a 2:1. My point is to ask you to seriously consider whether you truly are ready to start research or whether you are going to have to spend months gaining the basic undergraduate knowledge you should have had on day one. Only you can know this.

You already have three degrees so I don't know whether a Neuroscience specific Masters will help or not. You would need to ask. You should try and see if the person you applied to is willing to give you feedback on your application.