There can absolutely be a conflict between UX and SEO - for several reasons. I will touch on two of them:
UX can affect KPIs which, in turn, affect SEO
The way a website is designed, how information is presented, how intuitive it is to navigate the content - these are all elements that have a direct impact on KPIs (Key Performance Indicator) such as CTR (click through rate), bounce rate, time on site, and pages viewed per visit. Those same KPIs - especially CTR and bouncerate - have a direct impact on search engine ranking.It is a well known fact that Google attributes somewhat more weight to content that appears "above the fold" (e.g. higher up on the page) than content that is further down on the page. The question is this - does the 'above the fold' rule apply only visually or at the code level as well?
After 2 decades in this industry, I'm included to think it's both.
There are often several ways to code the design and layout of a website that result in the same visual appearance but are very different at the code level. In my experience, all other SEO factors being equal, pages that have less code before the actual content tend to rank better.
Yes there can be and are a conflict but there is also several things that make them related.