nRF9160 PSM Sleep for Longer than 8 Hours

Question

With TAU set to 24 hours, when we wake up every 8 hours, everything works fine. When we extend to 12 hours, it takes longer than 10 seconds for a connection to be established. And when we try, we get the following errors waiting for the connection to come online:

Waiting for LTE
[12:01:04.373,016] <wrn> lte_lc: Connection evaluation failed with reason: 5
LTE Connected
[12:01:04.772,155] <wrn> lte_lc: Connection evaluation failed with reason: 4
lte_lc_conn_eval_params_get, error: 4

While it shows connected (semaphore obtained), the data isn't sent. It's only after we send 3 UDP messages that we get the following "RRC mode: Connected."

What would cause the modem to disconnect from the network after 12 hours vs 8 hours?

bool lteConnected(int m_secs) {
bool connected = false;
struct lte_lc_conn_eval_params params = {0};
int err;

   printk("Waiting for LTE\n");
   err = lte_lc_conn_eval_params_get(&params);
   if (!err) {
      if (params.rrc_state == LTE_LC_RRC_MODE_CONNECTED) {
         printk("Already connected\n");
         return true;
      } else  
		   printk("Waiting for connection\n");
   } else
	   printk("Error getting LTE connection eval params\n");

	if (k_sem_take(&lte_connected, K_MSEC(m_secs)) == 0) {
      printk("LTE Connected\n");
      connected = true;
   } else {
      printk("LTE Timeout\n");
   }
   return connected;
}

## PSM
CONFIG_LTE_PSM_REQ_RPTAU="00111000"
CONFIG_LTE_PSM_REQ_RAT="00000000"

## eDRX
CONFIG_LTE_EDRX_REQ_VALUE_LTE_M="1001"

Network registration status: Connected - roaming
PSM parameter update: TAU: 86400, Active time: 0
eDRX parameter update: eDRX: 163.839996, PTW: 2.560000