Install Lifetime of Ipsec Side2Side VPN

[DerBaer]

Hey community,

i configured a Side to Side VPN between my Pfsense and an Fritzbox.
I used this german guide to create the side2side VPN http://blog.mincore.de/2018/06/22/ipsec-site-to-site-zwischen-pfsense-und-fritzbox-ab-fritzos-6-5x/

The VPN works, but there is something i dont understand.
I created the VPN with a lifetime of 28800 seconds, but under Status-> Ipsec in my Pfsense there are 3 Lifetimes listed, when i click on "show child SA Entries".
"Rekey" and "Life" Lifetimes are set to 28800, but there is a third lifetime "install" listed. This lifetime always resets itself after 2-3 Minutes to 0 and runs for 2-3 Minutes again (After that it resets itself again).
Is this normal behavior or is somethin wrong with the Side2Side VPN?
Under SystemLogs-> Ipsec i can find the following Entrys:

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```Sep 20 16:30:50 	charon 		01[CFG] vici client 277 connected
Sep 20 16:30:50 	charon 		15[CFG] vici client 277 registered for: list-sa
Sep 20 16:30:50 	charon 		14[CFG] vici client 277 requests: list-sas
Sep 20 16:30:50 	charon 		15[CFG] vici client 277 disconnected
Sep 20 16:30:51 	charon 		15[NET] <con1000|25> received packet: from (RemoteIP) [4500] to (PFsenseIP)[4500] (444 bytes)
Sep 20 16:30:51 	charon 		15[ENC] <con1000|25> parsed QUICK_MODE response 880152074 [ HASH SA No KE ID ID N((24576)) ]
Sep 20 16:30:51 	charon 		15[CFG] <con1000|25> selecting proposal:
Sep 20 16:30:51 	charon 		15[CFG] <con1000|25> proposal matches
Sep 20 16:30:51 	charon 		15[CFG] <con1000|25> received proposals: ESP:AES_CBC_256/HMAC_SHA1_96/MODP_2048/NO_EXT_SEQ
Sep 20 16:30:51 	charon 		15[CFG] <con1000|25> configured proposals: ESP:AES_CBC_256/HMAC_SHA1_96/MODP_2048/NO_EXT_SEQ
Sep 20 16:30:51 	charon 		15[CFG] <con1000|25> selected proposal: ESP:AES_CBC_256/HMAC_SHA1_96/MODP_2048/NO_EXT_SEQ
Sep 20 16:30:51 	charon 		15[CHD] <con1000|25> CHILD_SA con1000{27} state change: CREATED => INSTALLING```
code_text

Do you know if this is normal?