Proposed block and mevboost timed out

I've been using mevboost for some time and have proposed some blocks with mev normally. However a couple of days ago I noticed that mevboost timed out, fortunately my CL proposed the block but without mev.
Is there anything abnormal about this or is it just a random thing?
Posting logs from nimbus and mevboost below.

```
Jun 14 22:42:36 validator nimbus_beacon_node[2904275]: WRN 2023-06-14 22:42:36.990+00:00 Could not obtain blinded execution payload header topics="beacval" error="getBlindedExecutionPayload timed out" slot=6663211 validator_index=109040 head=a346460e:6663210

Jun 14 22:42:36 validator nimbus_beacon_node[2904275]: INF 2023-06-14 22:42:36.992+00:00 Payload builder error topics="beacval" slot=6663211 head=a346460e:6663210 validator=afe1ab14 err="getBlindedExecutionPayload timed out"
```

```

Jun 14 22:42:36 validator mev-boost[1063926]: time="2023-06-14T22:42:36Z" level=info msg="best bid" blockHash=0xdaee9f006ecc1b2442c303abbb0507c2373cc65a5b822fa7b4f95b44b881a2b4 blockNumber=17481214 method=getHeader parentHash=0xe5ff879d961c5d3ea5bfb455c65baebd92de7fa39c7df3e201d90b902cf180b2 pubkey=0xafe1ab147ad6b91cd77a79c4762bdf80a410c35e523a88b23082995b3a81cd633a05b08d987b6899b827ff9f50a30f41 relays=https://0x8b5d2e73e2a3a55c6c87b8b6eb92e0149a125c852751db1422fa951e42a09b82c142c3ea98d0d9930b056a3bc9896b8f@bloxroute.max-profit.blxrbdn.com/ slot=6663211 txRoot=0x3297a8df11f50691e7f7362be69739d6ccbf1d1c147b2f42f24a69937cbc7628 value=0.030212656458174002 version=v1.5.0

Jun 14 22:42:36 validator mev-boost[1063926]: time="2023-06-14T22:42:36Z" level=info msg="http: GET /eth/v1/builder/header/6663211/0xe5ff879d961c5d3ea5bfb455c65baebd92de7fa39c7df3e201d90b902cf180b2/0xafe1ab147ad6b91cd77a79c4762bdf80a410c35e523a88b23082995b3a81cd633a05b08d987b6899b827ff9f50a30f41 200" duration=0.142337 method=GET path=/eth/v1/builder/header/6663211/0xe5ff879d961c5d3ea5bfb455c65baebd92de7fa39c7df3e201d90b902cf180b2/0xafe1ab147ad6b91cd77a79c4762bdf80a410c35e523a88b23082995b3a81cd633a05b08d987b6899b827ff9f50a30f41 status=200 version=v1.5.0
```

Start by tracing the mev-boost builder-header request and the Nimbus getBlindedExecutionPayload timeout using the supplied logs. Compare the timeout behavior with the documented request flow and determine whether the fallback is expected; done means the cause and expected behavior are established, with a reproducible test or a clearly documented explanation.

Written by the indexing model from the issue text.