APs not rebooting after ISSU Upgrade from ver 17.3.3 to 17.3.4

[AnilKumar95946]

Hello Guys,

I am facing with a strange issue. While upgrading the WLC (cisco 9800-CL) using ISSU (GUI)from version 17.3.3 to 17.3.4. APs are not resetting themselves and as a result remaining on the old code(17.3.3). I need to manually reset the AP to take effect. I want to do AP upgrade in a staggered manner to minimize the downtime. All the steps are completing successfully and no error logs generating. Controller is reaching SSO state without any issue.

AP Name Primary Image Backup Image Predownload Status Predownload Version Next Retry Time Retry Count
-------------------------------------------------------------------------------------------------------------------------------------------------------
TestAP1 17.3.4.30 17.3.3.26 None 0.0.0.0 N/A 0   [ Manually Reset Done]
TestAP2 17.3.3.26 17.3.4.30 None 0.0.0.0 N/A 0

Test-wc-01#sh ver | in 17.3
Cisco IOS Software [Amsterdam], C9800-CL Software (C9800-CL-K9_IOSXE), Version 17.3.4, RELEASE SOFTWARE (fc3)

APs Model: 9120AXI

Could you please help me in troubleshooting this issue.

[Haydn Andrews]

Confirming you followed the steps in this guide

https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/17-2/config-guide/b_wl_17_2_cg/in_service_software_upgrade.pdf

what's the output of show issu state detail

[AnilKumar95946]

Hi Andrews

I used the mentioned approach given in doc using GUI. 

Output 

Test-wc-01#sh issu state detail
Current ISSU Status: Enabled
Previous ISSU Operation: Successful
=======================================================
System Check Status
-------------------------------------------------------
Platform ISSU Support Yes
Standby Online Yes
Autoboot Enabled Yes
SSO Mode Yes
Install Boot Yes
Valid Boot Media Yes
=======================================================
No ISSU operation is in progress

[Arshad Safrulla]

Can you give the below command to force upgrade the AP's

ap image upgrade

Do not use ISSU unless you tested it in a test environment and familiar with the complete process. If you read the document which Hayden shared previously it states that if a HA event occurs during the ISSU, it will completely halt the AP upgrade process.