Unable to input Chinese characters (Microsoft Pinyin) after inputting 34 half-width characters

STDAPI FTextStoreACP::GetText(LONG acpStart, LONG acpEnd, __RPC__out_ecount_part(cchPlainReq, *pcchPlainOut) WCHAR *pchPlain, ULONG cchPlainReq, __RPC__out ULONG *pcchPlainOut, __RPC__out_ecount_part(ulRunInfoReq, *pulRunInfoOut) TS_RUNINFO *prgRunInfo, ULONG ulRunInfoReq, __RPC__out ULONG *pulRunInfoOut, __RPC__out LONG *pacpNext)
{
	// ...

	if(prgRunInfo && ulRunInfoReq > 0)
	{
		// We only edit text that's been stripped of any markup, so we have no need to provide multiple runs.
//		prgRunInfo[0].uCount = FMath::Min(static_cast<uint32>(ulRunInfoReq), Length);
		prgRunInfo[0].uCount = FMath::Min(static_cast<uint32>(cchPlainReq), Length);	// add
		prgRunInfo[0].type = TS_RT_PLAIN;
		++(*pulRunInfoOut);
	}

//	*pacpNext = BeginIndex + Length;
	*pacpNext = BeginIndex + FMath::Min(static_cast<uint32>(cchPlainReq), Length);	// add

	return S_OK;
}