Besides providing the data requested in previous comment (which would be still useful for troubleshooting) try to run current master or 5.3 with the next commits backported:
* a4f8c0291bfd32752c0c2c323f618c6ac0c91d53 * 125031daeade9dab5c36b912dda65700d95c4c6a * 8965ff07f2e9fa105fc56896eed9caf4b6faf261