Cluster Join Node- Error

Hi Dear Percona Support Team,
When I joined a node to the cluster, it started with an SST process. After that, I noticed the presence of gcache.page files when I checked the datadir. Below are the relevant
Actually Database size sync another Databases. Why this file increases?

configurations:
MYSQL Settings:
[mysqld]
server-id=61
datadir=/DB/mysql
socket=/var/run/mysqld/mysqld.sock
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
log-bin=/LOG/cluster-binlog
log_slave_updates
expire_logs_days=7
WsrepConf:
[mysqld]
wsrep_provider=/usr/lib/galera3/libgalera_smm.so
wsrep_cluster_address=gcomm://10.100.2.61,10.100.2.62,10.100.2.63
wsrep_provider_options=“gcache.size = 25G”
binlog_format=ROW
default_storage_engine=InnoDB
wsrep_slave_threads= 12
wsrep_log_conflicts
innodb_autoinc_lock_mode=2
wsrep_node_address=10.100.2.61
wsrep_cluster_name=test-cluster
wsrep_node_name=test-cluster-node-1
pxc_strict_mode=PERMISSIVE
wsrep_sst_method=xtrabackup-v2
wsrep_sst_donor=test-cluster-node-3
wsrep_sst_auth=“sstuser:s3cretPass”

-rw-r----- 1 mysql mysql 134217728 Aug 27 15:15 gcache.page.001888
-rw-r----- 1 mysql mysql 134217728 Aug 27 15:16 gcache.page.001889
-rw-r----- 1 mysql mysql 134217728 Aug 27 15:17 gcache.page.001890
-rw-r----- 1 mysql mysql 134217728 Aug 27 15:18 gcache.page.001891
-rw-r----- 1 mysql mysql 134217728 Aug 27 15:18 gcache.page.001892
-rw-r----- 1 mysql mysql 134217728 Aug 27 15:19 gcache.page.001893
-rw-r----- 1 mysql mysql 134217728 Aug 27 15:20 gcache.page.001894
-rw-r----- 1 mysql mysql 134217728 Aug 27 15:20 gcache.page.001895
-rw-r----- 1 mysql mysql 134217728 Aug 27 15:21 gcache.page.001896
-rw-r----- 1 mysql mysql 134217728 Aug 27 15:22 gcache.page.001897
-rw-r----- 1 mysql mysql 134217728 Aug 27 15:23 gcache.page.001898
-rw-r----- 1 mysql mysql 134217728 Aug 27 15:23 gcache.page.001899
-rw-r----- 1 mysql mysql 134217728 Aug 27 15:24 gcache.page.001900
-rw-r----- 1 mysql mysql 134217728 Aug 27 15:24 gcache.page.001901
-rw-r----- 1 mysql mysql 0 Aug 23 15:24 grastate.dat
-rw-r----- 1 mysql mysql 265 Aug 26 09:23 gvwstate.dat
-rw-r----- 1 mysql mysql 138242 Aug 26 07:07 innobackup.move.log
-rw-r----- 1 mysql mysql 549045 Aug 26 07:07 innobackup.prepare.log

Have you read through this blog post? All You Need to Know About GCache (Galera-Cache)

gcache will not release the pages until it is safe to do so (until the data has been safely replicated to all the nodes).