Does eclair support transfers in invoice without payment_secret?

[nayuta-ueno]

I wanted to do a non-MPP transfer, so I modified the LND to create an invoice with only feature 9(var_onion_optin).
I executed the transfer command from eclair with the following connection(testnet):

[A:eclair]---->[B:LND]---->[C:LND]

A: sender
B: relayer
C: payee (create a non-MPP invoice)

I read the logs for A(sender) and B(relayer). A did not send update_add_htlc and B did not receive it.
If I enable payment_secret on the invoice(feature 14), the transfer was successful.
Does eclair support transfers in invoice without payment_secret?

When Phoenix(mainnet) is the sender, update_add_htlc is sent, but the LND(A) was in error and returned update_fail_htlc.
The cause is unknown.

[Phoenix]---->[ACINQ]---->???---->[LND(A)]--->[LND(B)]

For now, I am trying to make feature 14 (payment_secret) mandatory for eclair/phoenix.

[t-bast]

Bolt 11 invoices MUST have a payment_secret, even when MPP isn't used, otherwise the payment is rejected. The payment_secret is independent of MPP, you should create invoices with features 9 (var_onion_optin) and 14 (payment_secret), even if the invoice doesn't support 16 (basic_mpp).

[nayuta-ueno]

This was the only description I could find for payment_secret in Bolt11.

A reader:
  ...
  - if there is a valid `s` field:
    - MUST use that as [`payment_secret`](04-onion-routing.md#tlv_payload-payload-format)

[nayuta-ueno]

Sorry, I missed this one:

A writer:
  ...
  - MUST include exactly one `s` field.