Ok, I found Scan Interrupted at 98% - #4 by investguy and used the proposed workaround : use greenbone/ospd-openvas:22.4.1 instead of stable for ospd-openvas. All seems fine now ! 
I can add that I also came accros the problem with Redis (unable to dump the .rdb file due to permission issue) but I already solved it by patching the redis.conf file to redirect the .rdb file to a writable folder.