Cannot make it work with W3 Total Cache

Hello. I am trying to set up AdRotate and W3 Total Cache in order to work together, following the instructions I found in the AdRotate Settings area. In particular, I have added the suggested line of code to my wp-config.php file but I cannot enable “Late initialization” in the Page cache advanced settings of W3 Total Cache: I can see the tick box but I cannot select it.

I am wondering if anyone knows what could I try to enable “Late initialization”, which should let my ads rotate again even with page caching. Maybe I need to change some other settings in order to make “Late initialization” tickable again, but so far I could not find any help on that. Thanks in advance for your help.

https://www.ads-software.com/plugins/adrotate/