pv not printing to a pipe

Executing this command displays the output on console. But when output is piped to another command it does not work. See below. (pv -F $'%t %r %e\n' /dev/nvme0n1p1 | gzip -c >/run/test.img ) 0:00:01 [25.2MiB/s] ETA 0:00:18 0:00:02 [23.7MiB/s] ETA 0:00:18 0:00:03 [ 100MiB/s] ETA 0:00:07 0:00:04 [ 199MiB/s] ETA 0:00:01 Now see below same command output is piped to another command and it does not display anything at all. I have redirected stderr to stdout and passed it to tr -d so it can remove ":[ ] " characters. (pv -F $'%t %r %e\n' /dev/nvme0n1p1 | gzip -c >/run/test.img ) 2>&1 | tr -d ':[]' See below, same command, but I am not redirecting stderr to stdout, Also if I don't redirect stderr to stdout, with the same command above, I don't get desired results, see below, using tr -d to delete following characters ":[]" but does not work. You can see tr -d command is completely ignored. (pv -F $'%t %r %e\n' /dev/nvme0n1p1 | gzip -c >/run/test.img ) | tr -d ':[]' 0:00:01 [25.2MiB/s] ETA 0:00:18 0:00:02 [23.7MiB/s] ETA 0:00:18 0:00:03 [ 100MiB/s] ETA 0:00:07 0:00:04 [ 199MiB/s] ETA 0:00:01 I have spent countless hours to figure this out, searched on stackexchange and all the forums but I cannot get my head around, how to fix this. I have also tried using file Descriptor 2>&3 but still no luck.