IMHO, which was confirmed by Meghan's own words yesterday, she needed more time. As was claimed by many posters since the news of the engagement, a year or two in UK before the engagement would do her a world of good. She had absolutely no idea how the BRF works, how the day-to-day work looks like, how familial relations are, she had no support system in place. And how could she, she was engaged and jumped into the royal work a month after moving to UK. At that point they were in a serious relationship for a year, and they were doing things long distance. Had they given this more time, she would know what she was getting into.
And before I'm attacked, yes, I think there is a lot that the palace, and by that I mean the Sussexes/Cambridges offices did wrong. I understand why no one would think to lead a 35-year old former actress by hand, but they both clearly needed more support in place. Though we will never know if the advice and support was there, they just weren't willing to take it and use it, as it didn't fit their views. Meghan once claimed she ignored her friends' advice, so why not do the same with palace officials?
My guess is they didn’t want or like the advice they were given, as you suggested.
And if they didn’t get EXACTLY what they wanted, how they wanted it....that translated to no support at all.
As you said, Meghan ignored her own friends advice.