json.loads(x) works offline but not online - json

Question

I'm doing a download of information from a router. The received data is a string with a json-like structure.
For example, using netmiko I ask the router for information, and this is what I get (just doing a simple print).
rx = conn2rtr.send_command('info json\n')
The rx string is the following.
print(rx)
{
"nokia-state:version-number": "B-21.7.R2",
"nokia-state:version-string": "TiMOS-B-21.7.R2 both\/x86_64 Nokia 7750 SR Copyright (c) 2000-2021 Nokia. All rights reserved. All use subject to applicable license agreements. Built on Wed Sep 15 12:57:16 PDT 2021 by builder in \/builds\/c\/217B\/R2\/panos\/main\/sros"
}
I do some treatment on the string, such as...
rx = rx.replace("\r", "")
rx = rx.replace("\n", "")
rx = rx.replace("\0", "")
rx = f"'{rx}'"
And after printing again, this is what I get:
'{ "nokia-state:version-number": "B-21.7.R2", "nokia-state:version-string": "TiMOS-B-21.7.R2 both\/x86_64 Nokia 7750 SR Copyright (c) 2000-2021 Nokia. All rights reserved. All use subject to applicable license agreements. Built on Wed Sep 15 12:57:16 PDT 2021 by builder in \/builds\/c\/217B\/R2\/panos\/main\/sros"}'
If I copy+paste that resulting string into the python shell, meaning, working offline, I can convert that into a dictionary, such as:
In [58]: h = '{ "nokia-state:version-number": "B-21.7.R2", "nokia-state:version-string": "TiMOS-B-21.7.R2 both\/x86_64 Nokia 7750 SR Copyright (c) 2000-2021 Nokia. All rights reserved. All use subj
...: ect to applicable license agreements. Built on Wed Sep 15 12:57:16 PDT 2021 by builder in \/builds\/c\/217B\/R2\/panos\/main\/sros"}'
In [59]: json.loads(h)
Out[59]:
{'nokia-state:version-number': 'B-21.7.R2',
'nokia-state:version-string': 'TiMOS-B-21.7.R2 both/x86_64 Nokia 7750 SR Copyright (c) 2000-2021 Nokia. All rights reserved. All use subject to applicable license agreements. Built on Wed Sep 15 12:57:16 PDT 2021 by builder in /builds/c/217B/R2/panos/main/sros'}
However, if I try to do it on-the-fly, meaning doing a json.loads(rx) on the received data from the router, I get the error Expecting value: line 1 column 1 (char 0).
There is clearly something wrong with the string rx that goes away if I copy+paste that, which is bothering the json.loads() method.
What else can I check to solve this?
thanks.