Unable to reproduce the issue in MacBook Pro (Retina, 15-inch, Mid 2014), 10.12.6 and Win-10 using chrome reported version #61.0.3163.79 and latest canary #63.0.3213.0.

Following are the steps followed to reproduce the issue.
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1. Navigated to chrome://settings/?search=spelling+errors and ensured "Use a web service to help resolve" is toggled to off.
2. Navigated to URL: https://www.w3schools.com/tags/tryit.asp?filename=tryhtml_form_submit and typed "hjhk ".
3. Pressed the right mouse button over hjhk and selected "Ask Google for Suggestions".
4. Clicked enable.
5. Clicked to the right of hjhk and typed "hjhk " again.
6. Observed that hjhk was underlined in red as expected.

Note: There were no hjhk underlined in others tabs.

Attaching screen cast for reference.

sitsofe@ - Could you please check this issue on latest canary #63.0.3213.0 by creating a new profile without any apps and extensions and please let us know if the issue still persist or not.

Thanks...!!

Attaching screencast

Deleted: 763634.mp4 1.5 MB

	763634.mp4 1.5 MB View Download

Just reproduced with the following and a fresh profile:
Google Chrome	63.0.3214.0 (Official Build) canary (64-bit)
Revision	21dea15ba6117af0b06bd89c6dd6f427a016423d-refs/heads/master@{#501490}
OS	Mac OS X

/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --user-data-dir=/tmp/chromedatadir/ 

Also notice how in the screencast the person typing fails to type a space after hjhk which would have triggered the red underline.

Thank you for providing more feedback. Adding requester "krajshree@chromium.org" to the cc list and removing "Needs-Feedback" label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Note the command run that I stated was old, it should have been: /Volumes/Google\ Chrome\ Canary/Google\ Chrome\ Canary.app/Contents/MacOS/Google\ Chrome\ Canary --user-data-dir=/tmp/chromedatadir/ 

Seems like a blink issue.

Has anyone managed to successfully reproduce this issue?

Thank you I will do that and I appreciate your responses I didn't realise
that I actually had star added to it again THANK YOU....

Route to UI>Browser>Language>Spellcheck, since this may be spell checking web service
issue instead of Blink.

I could not reproduce this issue. However, latency of appearing red waveline is long.

rouslan@, can we have metrics of latency, # of clients, etc of spell checking
web service?

"Ask Google for Suggestions" does not deal well with gibberish (hjhk). In addition, the feature does not do well without any context, because it's a contextual spelling checker. If Google cannot figure out what you meant to write, it will not suggest any spell corrections and will not underline your word as misspelled. This is a tradeoff between underlining everything that spellcheck has  seen rare (hjhk) and being more relaxed when new terms appear in the world (skrillex). If you Googke hjhk, you will see several legitimate uses in such contexts as youtube video tags or game nicks. Not sure what's the best course of action here.

@rouslan: phew! I'm sure I originally saw this problem with something other than gibberish but I can't for the life of me remember what the context was but thanks for the explanation. I'll respond further on the original issue.