One more information:
size of all the deleted files changes (grows)
Every 2.0s: lsof +L1 | grep foreman-proxy/proxy.log. Thu Jul 4 14:19:36 2019
ruby 62733 foreman-proxy 9u REG 252,0 74002390 0 1313894 /var/log/foreman-proxy/proxy.log.1 (deleted)
ruby 62733 foreman-proxy 15u REG 252,0 75641376 0 1318313 /var/log/foreman-proxy/proxy.log.1 (deleted)
ruby 62733 foreman-proxy 20u REG 252,0 74510136 0 1318154 /var/log/foreman-proxy/proxy.log.1 (deleted)
ruby 62733 foreman-proxy 27u REG 252,0 74369050 0 1317781 /var/log/foreman-proxy/proxy.log.1 (deleted)
ruby 62733 foreman-proxy 32u REG 252,0 74306006 0 1314081 /var/log/foreman-proxy/proxy.log.1 (deleted)
ruby 62733 foreman-proxy 33u REG 252,0 74142990 0 1318979 /var/log/foreman-proxy/proxy.log.1 (deleted)
ruby 62733 foreman-proxy 39u REG 252,0 74002745 0 1319069 /var/log/foreman-proxy/proxy.log.1 (deleted)
Every 2.0s: lsof +L1 | grep foreman-proxy/proxy.log. Thu Jul 4 14:22:30 2019
ruby 62733 foreman-proxy 9u REG 252,0 78634660 0 1313894 /var/log/foreman-proxy/proxy.log.1 (deleted)
ruby 62733 foreman-proxy 15u REG 252,0 80273646 0 1318313 /var/log/foreman-proxy/proxy.log.1 (deleted)
ruby 62733 foreman-proxy 20u REG 252,0 79142406 0 1318154 /var/log/foreman-proxy/proxy.log.1 (deleted)
ruby 62733 foreman-proxy 27u REG 252,0 79001320 0 1317781 /var/log/foreman-proxy/proxy.log.1 (deleted)
ruby 62733 foreman-proxy 32u REG 252,0 78938409 0 1314081 /var/log/foreman-proxy/proxy.log.1 (deleted)
ruby 62733 foreman-proxy 33u REG 252,0 78775393 0 1318979 /var/log/foreman-proxy/proxy.log.1 (deleted)
ruby 62733 foreman-proxy 39u REG 252,0 78635148 0 1319069 /var/log/foreman-proxy/proxy.log.1 (deleted)