I have orian’s sun seal with a 9 second increased duration equipped and 5/5 in enduring hope and 3/5 in healing rites. This should boost sigil of hope’s duration to 40 seconds. With Sun seal cast sigil every 10 seconds i should always have 4 sigils up but I don’t it, i have mostly 3 and occassionally 4.
Whilst this bug was present i moved one point into Last wish to try and maintain 4 sigils more frequently, but noticed that no kills were awarding a sigil, it still refreshed only on sun seal casting the sigil. I removed sun seal and ran a number of arena maps in monoliths and gained 0 sigils during any kills
Healing Rites doesn’t increase duration of the Sigils. Basically what it does is when you get hit with big damage and a sigil is consumed (Faith passive), you get a 25% bonus to healing effectiveness (for all spells) for 2/4/6/8/10 seconds.
So your Sigils only last 34 seconds, and the amount of sigils you see is correct.
Iceberg is correct about Last Wish, you need Sigils of Hope on your skill bar in order to get sigils from kills.