[BUG] sentinel error after second switch master

[imazzeii]

Describe the bug

I have created a sentinel cluster with docker compose made of 3 sentinels (ports 5000, 5001, 5002), 1 master (port 6385) and 2 slaves (6386 and 6387); then I connect a client to sentinel node 5000 and start to execute the following steps:

time	action
t0	delete key 'mykey'
t1	sleep 3 seconds
t2(+3 sec)	set mykey=myvalue
t3	sleep_t3 3 seconds
t4(+6 sec)	dispatch sleep command 30 seconds to redis 6385 (using a separate connection)
t5	sleep_t5 7 seconds
t6(+13 sec)	set mykey=newvalue
t7	sleep_t7 50 seconds
t8(+63 sec)	get new master config (using a separate connection)
	dispatch sleep command 3000 seconds to new redis master (using a separate connection)
t9	sleep_t9 5 seconds
t10(+70sec)	set mykey=newvalue

so at time t4 master on port 6385 enters debug mode for 30 seconds and sentinels elect a new master (everything works fine), but at time t8 the new master enters debug mode for 3000 seconds and sentinels are unable to elect a new master; if a separate client tries to connect it either hangs or connects but cannot modify data (receice error message: readonly, you can't write against a read only replica)

To reproduce

1. (edit) download files from https://fastupload.io/f993031e9a01f2fd
2. extract the attached file master-slave-sentinel.zip in a folder and start the sentinel cluster: docker compose -f docker-compose-sentinel.yml up -d
3. add the entry 127.0.01 host.docker.internal in your hosts file
4. copy the attached file test-lettuce-0.0.1-SNAPSHOT-jar-with-dependencies.jar and run with the following command: java -jar test-lettuce-0.0.1-SNAPSHOT-jar-with-dependencies.jar (the source files can be found in attachment test-lettuce-0.0.1-SNAPSHOT-sources.jar)
5. alternatively, perform the previously described steps manually

see the attachement for the console logs

tools used: redis 7.2.5-alpine, docker desktop 4.28.0 (windows)
for the client: java jre 17, lettuce-core 6.3.1

tested on :

• windows 10 - Intel(R) Core(TM) i7-10510U
• windows 10 - Intel(R) Core(TM) i7-1260P

Expected behavior

the expected behaviour is that a new master is elected correctly after the second elected master stop working

Additional information

Any additional information that is relevant to the problem.

[imazzeii]