I read the June 30th 10-Q filing from Sonder.

The liabilities exceed the assets with 400 million USD.
Marriott gave Sonder a cash injection (key money) of 15M USD in two tranches, November 2024 and April 2025. The main expectation from the Marriott agreement seems to be increased revenue and reduced cost from the access to the Marriott platforms. August 2025 there was an agreement to delay the settlement of fees to Marriot for 12 months, so Marriott is also in the red for that, but it is not mentioned how much that is. The integration costs to enter Marriott's platforms was 3.7M USD in 1H 2025, so that is probably not what broke the camel's back. Total operating costs were 336M USD in the 6 months. Revenue was 266M USD.

The direct revenue (mainly Marriott driven) takes quite a hit in 2025, but the indirect revenue (OTAs) is increasing, but overall the revenue is down.