@Nafrudin: It’s most likely due to the difference in server time. For example, a broker whose server is located in Jakarta (GMT +7) has a market watch (on MetaTrader 4) that differs from a broker with a server in London (Europe, GMT +1). There is a 6-hour difference between Jakarta and London.
Please check on the MT4 market watch to see where the server location time is. I've provided an example screenshot of the market watch below.

@Safrudin: True.
Can Indonesian server brokers change their server to join the European server for example? How do I do it?
It cannot be changed. Server determination is the right of the broker and the broker determines the server used based on the type of account offered. So if you want to change the time to another server, you must switch to a different account type. For more details, please consult the customer service (CS) of the forex broker in question to inquire about the server time zone.
@ Nafrudin:
Sorry, what exactly is the 80% difference in? Is it the open, high, low, or close price?
Price movements of candlesticks can indeed differ between brokers because the servers and opening hours are different, so the open, high, low and close prices can also differ. However, the price differences are not too significant.
Sorry, I don’t know the regulations of the brokers you mentioned.
For the safety of your trading and funds, we recommend choosing brokers that are already regulated by credible international regulatory bodies, namely: CFTC, NFA, FCA, FSA, FINMA, MiFID, ASIC and FMA.
A credible regulatory body is one that has been tested and is internationally recognized, and imposes strict sanctions on brokers if they violate agreed upon provisions. The regulatory body is also responsible for the security of client funds.