Pending rewards not estimated correctly

[UjCbFwtBayFM]

Description

On 06/01 the Pending Rewards counter reset, as it does every month. It was then at 0 (zero).
During the next days the counter began to rise again as I got ads. It steadily went up with each delivered ad until it reached 4.1 BAT on 06/15 in the morning but in the evening of the same day I noticed the counter went back significantly to ~1.1 BAT. I assumed at first it was yet another display bug, so I waited a few days to see how it'd evolve. It went back up a bit, but still far from the previous value.
Today I decided to cross-check with Brave's logs in %localappdata%\BraveSoftware\Brave-Browser\User Data\Default\ads_service\confirmations.json. While Brave itselfs says I'm at 1.462 BAT for June, ads_rewards.payments shows a balance of 1.1175 for the running month. I get the same value by adding transactions from transaction_history.transactions.

Steps to Reproduce

Unknown.

Actual result:

Expected result:

Reproduces how often:

Unknown.

Brave version (brave://version info)

Brave | 1.25.73 Chromium: 91.0.4472.106 (Official Build) (64-bit)
Revision | 574f7b38e4e7244c92c4675e902e8f8e3d299ea7-refs/branch-heads/4472@{#1477}
OS | Windows 10 OS Version 2004 (Build 19041.1052)

Version/Channel Information:

• Can you reproduce this issue with the current release? yes
• Can you reproduce this issue with the beta channel? no/unknown
• Can you reproduce this issue with the nightly channel? no/unknown

Other Additional Information:

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

Miscellaneous Information:

[UjCbFwtBayFM]

Update: on 07/01 estimated pending rewards in Brave was at 2.7 BAT. Today the payout for June was 5.6 BAT, making up for the "lost" BAT at the middle of the month.