lalsimulation 5.1.0 fails PhenomX test on arm64, Debian Buster

Description of problem

lalsimulation 5.1.0 fails PhenomX test on arm64, Debian Buster... but passes on Bullseye. (FAIL: test_phenomX.py once, FAIL: test_phenomX 3 times).

Expected behavior

clean build, like for other arches and bistro

Steps to reproduce

run builder

Log is here: https://hypatia.aei.mpg.de/lsc-arm64-buster/lalsimulation_5.1.0-1+deb10u0_arm64.--pbuilderlog

The underlying issue seems to be an error tolerance too tight in test_IMRPhenomXPHM_SpinTaylor (4 times)

Suggested solutions

increase error tolerances - or drop Buster