Powershell: Extract data between 2 strings, in the newest file in directory

My powershell script is supposed to do the following:

• Read the data from the newest log file in the directory

• Output only the relevant data in an output file on my desktop.

At the moment, i get the entire line everytime the word "lobbyid" appears in the document.

My code:

Get-ChildItem -Path  "C:\Program Files\Example\logs" |Sort-Object LastAccessTime -Descending | Select-Object -First 1 | Select-String –Pattern "lobbyid"| Select Filename,Line | Format-Table -wrap | Out-File $env:USERPROFILE\Desktop\output.txt -append'

On a log file containing

XXXXXXXXXXXXXXXXXXXXX
{"seqid":5,"lobbyid":"9A74E75D-2BCB-4750-BF3A-87BB4992DC2D","mm":{"status":7}
{"seqid":12,"lobbyid":"CFDAAA9C-F973-40CF-A477-143A5810061D","mm":{"status":10}
YYYYYYYYYYYYYYYYYYYYY

I get

{"seqid":5,"lobbyid":"9A74E75D-2BCB-4750-BF3A-87BB4992DC2D","mm":{"status":7}
{"seqid":12,"lobbyid":"CFDAAA9C-F973-40CF-A477-143A5810061D","mm":{"status":10}

But I would like the output

    Line 1: 9A74E75D-2BCB-4750-BF3A-87BB4992DC2D
    Line 2: CFDAAA9C-F973-40CF-A477-143A5810061D

Or something similar. I tried replacing "lobbyid" with 'lobbyid(.*?)mm' But that gave the same output.