Thank you Pavel for your reply (and sorry for the delay; I was expecting to receive an email notification that someone had replied but didn't get one).
I do have the latest version of the Secure Browser - 86.1.6938.199 - but the adblock is still missing for me!
The diagnostic info is here; thank you for looking into it for me.
executable_path=C:\Program Files (x86)\AVAST Software\Browser\Application\AvastBrowser.exe
profile_path=C:\Users\graha\AppData\Local\AVAST Software\Browser\User Data\Default
os_version=Windows 10 v2004 (x64)
av_version=20.9.2437
urlscanner_version=1.6.0.266
host_prefix=
browser_version=86.1.6938.199 (Official Build (64-bit))
cgid=213
cid=1102
uid=87a8cc32e437457f9df8d2fa1b66d8cc
Channel: stable
OS language: en-us
Browser language: en-US
Search Engine URL:
https://www.google.com/search?client=avast&q={searchTerms}Omaha version: 1.8.1065.0
Enabled extensions:
ahfgeienlihckogmohjhadlkjgocpleb : Web Store : 0.2
beghmmhchncjignfbfnemngnlnjdmbcb : Avast Anti-Fingerprinting : 2.5.181
dmfdacibleoapmpfdgonigdfinmekhgp : Avast SecureLine VPN : 1.5.1.839
ekmkelgimdicdgkflkakgmjcghgpdnji : Messaging : 1.1.0.156
kdhipfbocahipinepiahppeionfbahlg : Avast Video Downloader : 2.3.107
khoabckdcnciingnnklkfgdhnniefnod : Avast HTTPS Encryption : 19.6.4.136
kmediagceboldddnnajkcochbkfkedel : Avast Anti-Tracking : 1.23.0.675
kmendfapggjehodndflmmgagdbamhnfd : CryptoTokenExtension : 0.9.74
lhnnoklckomcfdlknmjaenoodlpfdclc : Avast Bank Mode : 1.2.0.182
mecokbmnofclapimmlnfegiohceoaocc : Avast Performance Manager : 1.2.220
mfehgcgbbipciphmccgaenjidiccnmng : Cloud Print : 0.1
mhjfbmdgcfjbbpaeojofohoefgiehjai : Chrome PDF Viewer : 1
nkeimhogjdpnpccoofpliimaahmaaome : Google Hangouts : 1.3.15
pkedcjkdefgpdelpbcmbmeomcjbeemfm : Chrome Media Router : 8620.824.0.0
Disabled extensions:
daihnpeaobniefegkjhignmingejpofa : Avast News Companion (Beta) : 1.1.15.1
emhginjpijfggbofeediiojmdlmlkoik : Avast Passwords : 2.0.4569
nmebbcjdbhgggcgohlnlgadkmjiedfbc : Avast Hack Check : 1.2.341