Incoming Rewards is not displaying correct estimates

[UjCbFwtBayFM]

Description

Follow up from previous issue which was closed.
Pending rewards counter again dropped sharply in the middle of September, days after August payout. Was back up at around 2.1 BAT at the end of the month (09/30). Pending rewards for the current month reset on 10/01, then Incoming rewards was showing 2.1 BAT incoming. Actual rewards received for September: more than 7 BAT.

Steps to Reproduce

1. Have pending rewards
2. Wait for payout day
3. Notice the difference.

Actual result:

Actual rewards is way off the estimated incoming rewards.

Expected result:

The Incoming Rewards should be relatively accurate

Reproduces how often:

Every other month.

Brave version (brave://version info)

Brave | 1.30.87 Chromium: 94.0.4606.71 (Official Build) (64-bit)
Revision | 1d32b169326531e600d836bd395efc1b53d0f6ef-refs/branch-heads/4606@{#1256}
OS | Windows 10 Version 2004 (Build 19041.1165)

Version/Channel Information:

• Can you reproduce this issue with the current release? Yes
• Can you reproduce this issue with the beta channel? N/A
• Can you reproduce this issue with the nightly channel? N/A

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? N/A
• Does the issue resolve itself when disabling Brave Rewards? N/A
• Is the issue reproducible on the latest version of Chrome? No

Miscellaneous Information:

[UjCbFwtBayFM]

Update: counter did not drop without any visible reason during the month, however there is a 88% discrepancy between what it was showing during the last day of October and the actual payout.