Core Text incremental redraw glitch: overlapping glyphs during editing

During editing in Pages (or Word) I am getting these glitches (see attachment). Started after the last update to Mac OS 26.3 (beta) Also removed 2 recent instalments (Blackhole audio driver and kDrive/Infomaniak, but trouble is still there.

27" iMac 2020 (Intel) i7 3,8 Ghz AMD Radeon Pro 5500 XT 8 GB 24 GB RAM macOS Tahoe 26.3 (=beta)

Tried restart in safe mode, checked fonts. Talked to aissistent to get a solution, but no ...)

Thx for any advice, Pieter (not a developer so please kee pit simple 🙏🏻)

This is the problem:

Core Text incremental redraw glitch: overlapping glyphs during editing
 
 
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