Is this a bug ?
this seems to be a bug. I've forwarded the description to the compiler engineers (DPD200529233). Once there is some progress, I'll update this thread.
Thank you for reporting & best regards,
this problem will be solved with next update release: 15.0 Update 3 (currently planned about end of April/beginning May).
For more complete information about compiler optimizations, see our Optimization Notice.