Oracle Data Guard Protection Modes

A Data Guard configuration always runs in one of three data protection modes (also called as redo transport rules)

By default, the protection mode is MAX PERFORMANCE. If you look above, MAX PERFORMANCE uses ASYNC redo transport and rest other protection modes uses SYNC protection mode.
Also, looking at MAX PROTECTION and MAX AVAILABILITY, we can say that the MAX PROTECTION mode is not used in real time. The main reason is if standby unavailable, primary will shut down.
The ultimate protection modes you must use are: MAX PERFORMANCE and MAX AVAILABILITY!

Switch from Max Performance to Max Availability Protection Mode

Verify the broker configuration, check if it’s enabled and make sure log apply is enabled

dgmgrl sys/oracle@proddb

show configuration 
show database proddb 
show database proddb_st 
edit database proddb_st set state=apply-on;

Change LNS mode from ASYN to SYNC

EDIT DATABASE proddb_st SET PROPERTY LogXptMode='SYNC'; 
EDIT CONFIGURATION SET PROTECTION MODE AS MaxAvailability;

Verify the broker configuration, check if it’s enabled and make sure log apply is enabled

dgmgrl sys/oracle@proddb

show configuration 
show database proddb 
show database proddb_st 
edit database proddb_st set state=apply-on;

Change LNS mode from ASYN to SYNC

EDIT DATABASE proddb_st SET PROPERTY LogXptMode='ASYNC'; 
EDIT CONFIGURATION SET PROTECTION MODE AS MaxPerformance;