THIS ONE IS TESTED WITH WORDPRESS XML FILE ONLY.
WORDPRESS Version 6.6.2

I designed built a website and 100s of posts and I was trying to IMPORT in to live site.
I took export and REPLACED globally some URLs, Like localhost to website name and some formatting, but when I imported on live website it got this ERROR.

354:846 Input is not proper UTF-8, indicate encoding !
Bytes: 0xA0 0x3C 0x61 0x20

when I checked on line 354 and 846 column, their was no non UTF-8 content, I checked everything everything was in UTF-8. still I was getting error.
I checked online no solution was available.

I deleted 354 line and imported it worked but stopped in

511:846 Input is not proper UTF-8, indicate encoding !
Bytes: 0xA0 0x3C 0x61 0x20

and on 511 line also same clear content but column field was same 846, then I figured out it was not 846 exactly.

it was like this Next</a>?<br/><br/>

and 846 was at end of Next and there was a invisible CTRL CHAR after </a>
I changed all field Next</a><br/><br/>

Globally and imported.

Wallha….! it Solved the issue.