Palpatine speaks to Kylo Ren:
PALPATINE: The Jedi apprentice still lives. Perhaps you have betrayed me. Do not make me turn my fleet against you.
I know Palpatine is stronger than Kylo Ren.
What makes Palpatine say that Kylo Ren betrayed him?
Palpatine speaks to Kylo Ren:
PALPATINE: The Jedi apprentice still lives. Perhaps you have betrayed me. Do not make me turn my fleet against you.
I know Palpatine is stronger than Kylo Ren.
What makes Palpatine say that Kylo Ren betrayed him?
What makes Palpatine say that Kylo Ren betrayed him?
He doesn't. He says [bold emphasis mine]:
Perhaps you have betrayed me.
Note the word "perhaps" which expresses that Darth Sidious sees the possibility that Kylo Ren may have betrayed him.
The reason is the previous sentence:
The Jedi apprentice still lives.
There are many possible reasons for Rey to still be alive, and one possibility is that Kylo Ren chose to let her live – which would be a form of betrayal towards Darth Sidious.
After all, Kylo Ren is a very powerful Sith, heir to the powerful Skywalker bloodline, whereas Rey is an untrained Jedi apprentice without the support of the Jedi Order to train her, starting her training about 15 years too late, and still Kylo Ren has not been able to kill her? Does that not sound suspicious? It sure does to Darth Sidious.