Open Fields' dialog's Functions page in Writer; press Help. Result: https://help.libreoffice.org/7.5/en-US/text/shared/05/err_html.html?System=WIN&DbPAR=WRITER&HID=modules/swriter/ui/fldfuncpage/FieldFuncPage
Reproduced for all tabs of the Insert > Field > More fields dialog: Version: 7.5.0.1 (X86_64) / LibreOffice Community Build ID: 77cd3d7ad4445740a0c6cf977992dafd8ebad8df CPU threads: 8; OS: Linux 5.15; UI render: default; VCL: gtk3 Locale: en-AU (en_AU.UTF-8); UI: en-US Calc: threaded
*** Bug 152890 has been marked as a duplicate of this bug. ***
The links now work for 7.5, since the documentation could be rebuilt following this commit: https://gerrit.libreoffice.org/c/core/+/145132
*** Bug 152942 has been marked as a duplicate of this bug. ***
Since the fixing commit is known, it's not WORKSFORME, but FIXED. Thanks!
Verified, <F1> Help resolves correctly with nightly build of 7.6.0 both with en-US local help pack installed and before that with the online delivered. Version: 7.6.0.0.alpha0+ (X86_64) / LibreOffice Community Build ID: d07b1cc8148140bd3a78103da668d002b9d266ab CPU threads: 8; OS: Windows 10.0 Build 19044; UI render: Skia/Vulkan; VCL: win Locale: en-US (en_US); UI: en-US Calc: threaded