Reproduction:
1) Open the project with unity a14
2) Look at the game view. IES profile is working. No errors
3) Open the project with unity a17 or a18
4) Errors in the console and IES are not rendering properly

Result: IES profile is unsigned in the light inspector, light looses IES rendering, the IES asset in the assets folder looses its icon.

Works with:
2021.2.a14 prepackaged HDRP
2021.2.a15 prepackaged HDRP

Doesnt work with:
2021.2.a17 prepackaged HDRP
2021.2.a18 prepackaged HDRP

Adding images of expected and actual results