Upstream bugs #84332 (compression of mysql.gtid_executed has been prevented when super_read_only = 1) and #84437 (super-read-only does not allow FLUSH LOGS on 5.7) are not longer happening in Percona Server 5.7.18, these two bugs were related with this hung. So this bug, can't be reproduced in PS 5.7.18.
Upstream bugs #84332 (compression of mysql.gtid_executed has been prevented when super_read_only = 1) and #84437 (super-read-only does not allow FLUSH LOGS on 5.7) are not longer happening in Percona Server 5.7.18, these two bugs were related with this hung. So this bug, can't be reproduced in PS 5.7.18.