To repro the failure, add 1.19.0 to tools/interop_matrix/client_matrix.py and run "tools/interop_matrix/run_interop_matrix_tests.py -l php --release v1.19.0". Seeing this error:
$ tools/interop_matrix/run_interop_matrix_tests.py -l php --release v1.19.0
START: Downloading images for language "php"
PASSED: pull_image_gcr.io/grpc-testing/grpc_interop_php:v1.19.0 [time=37.8sec, retries=0:0]
SUCCESS: All images downloaded successfully.
PASSED: php__php_v1.19.0:php:grpc-test:timeout_on_sleeping_server [time=1.3sec, retries=0:0]

Running test case ping_pong
Server returned too few responses
FAILED: php__php_v1.19.0:php:grpc-test:ping_pong [ret=1, pid=193874, time=17.1sec]

Running test case large_unary
Call did not complete successfully. Status object:
object(stdClass)#390 (3) {
["metadata"]=>
array(0) {
}
["code"]=>
int(14)
["details"]=>
string(14) "Connect Failed"
}
FAILED: php__php_v1.19.0:php:grpc-test:large_unary [ret=1, pid=193862, time=17.1sec]