I looked at the arrival times of the inv messages corresponding to these blocks at one of our monitor nodes. These monitor nodes receive and log inv messages but do not request the data for headers or blocks.
The following list of blocks contains in the first column the point in time at which the monitor received the first inv message for a certain block. The last column shows the number of peers from which the monitor node received the inv message.
23.03.2026 15:49:53.731 AntPool 941881 inv 9914
23.03.2026 15:49:56.669 Foundry 941881 inv 36
23.03.2026 15:51:46.992 ViaBTC 941882 inv 9904
23.03.2026 15:55:00.579 Foundry 941883 inv 8183
23.03.2026 15:55:05.038 Foundry 941882 inv 26
23.03.2026 16:02:30.817 Foundry 941884 inv 9087
There are two interesting aspects:
- An announcement for Foundry’s block at height 941881 was received before any announcement for a block at height 941882 was received.
- The monitor node received announcements for Foundry’s blocks at heights 941881 and 941882 only from a few peers. I don’t have an idea why. I would expect that nearly all peers should announce these blocks once they become part of the active chain.
EDIT: The majority of nodes announcing these blocks has in common that they announce btcd as their user agent. It seems that Bitcoin Core does not send inv messages for these blocks to our monitor.