🚨 Error: Cannot read property 'style' of null

Details
---
**Error report:** [link](http://go/ampe/CIrxtYSrl-ylvQE)
**First seen:** Mar 20, 2021
**Frequency:** ~ 49,911/day

Stacktrace
---

Error: Cannot read property 'style' of null

    at style (src/core/dom/style.js:121:10)

    at mutator (src/service/mutator-impl.js:221:8)

    at callback (src/service/vsync-impl.js:471:16)

    at callTask_ (src/service/vsync-impl.js:428:8)

Notes
---
`@rsimha` modified `src/core/dom/style.js:120-124` in [#21212](https://github.com/ampproject/amphtml/pull/21212) (May 16, 2019)
`@powerivq` modified `src/service/mutator-impl.js:219-221` in [#26638](https://github.com/ampproject/amphtml/pull/26638) (Feb 12, 2020)
`@jridgewell` modified `src/service/vsync-impl.js:471-472` in [#20836](https://github.com/ampproject/amphtml/pull/20836) (Feb 14, 2019)
`@rsimha` modified `src/service/vsync-impl.js:428-428` in [#23363](https://github.com/ampproject/amphtml/pull/23363) (Jul 17, 2019)

**Seen in:**
- 06-18 Stable (2132)
- 07-17 Stable (0150)
- 07-24 Experiment-B (0354)
- 07-24 Experimental (0354)
- 07-24 Nightly-Control (0354)
- 07-24 Stable (0354)
- +4 more

**Possible assignees:** `@powerivq`, `@rsimha`

/cc @ampproject/release-on-duty